Risa technologies 2D User Manual

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RISA

Rapid Interactive Structural Analysis

–2-

Dimensional

Version

10-General Reference

26632 Towne Centre Drive, Suite 210

Foothill Ranch,

California 92610

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5815

(949) 951

5848 (FAX)

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publication may be reproduced or transmitted i

n any means without the express written permission of

RISA Technologies, LLC.

We have done our best to insure that the material found in this publication is both useful and accurate.

However, please be aware that errors may exist in this publication, a

nd that RISA Technologies, LLC

makes no guarantees concerning accuracy of the information found here or in the use to which it may be

put.

Table of Contents

General Reference Manual

Table of Contents

Before You Begin

................................

...............

Overview

................................

...........................

Hardware Requirements

................................

..1Program Limits

................................

.................

License Agreement

................................

..........

Maintenance

................................

.....................

Installation

................................

........................

Application Interface

................................

.........

Main Menu

................................

........................

Shortcut Menu

................................

..................

Toolbars

................................

............................

Dynamic View Controls

................................

....11Shortcut Keys and Hot Keys

............................

Status Bar

................................

.........................

Windows

................................

...........................

Modes

................................

...............................

Aluminum

Databases

................................

......

Aluminum Shape Types

................................

...

Aluminum

Design

................................

............

Design Parameters

................................

...........

Aluminum Design Results

................................

Aluminum Detail Report

................................

...22Assumptions and Limitations

............................

Special Messages

................................

............

Boundary Conditions

................................

........

Creating and Modifying

................................

....24Boundary Conditions Spreadsheet

...................

Boundary Condition Options

............................

Footings at Boundary Conditions

.....................

Boundary Conditions at Wall Panels

................

Cold Formed Steel

Databases

........................

Custom vs. Manufacturer Shapes

....................

Cold Formed Shape Types

..............................

Cold Formed Steel

Design

..............................

Design Parameters

................................

...........

Phi Factors

................................

........................

AISI Steel Code Check Results

........................

Assumptions and Limitations

............................

Special Messages

................................

............

Concrete

Database

................................

..........

Rebar Layout Database

................................

....

Concrete

Design

................................

..............

Concrete Spans

................................

................

Concrete Design Parameters

Columns

..........

Concrete Design Parameters

Beams

.............

45T-

beam & L

beam Sections

..............................

Parabolic vs. Rectangular Str

ess Blocks

..........

Biaxial Bending of Columns

..............................

Limitations

General

................................

........

Limitations

ACI

................................

...............

Limitations

Canadian Code

............................

Limitations

Australian and N

Codes

.............

Limitations

British

................................

...........

Limitations

Euro

................................

..............

Limitations

Indian

................................

...........

Limitations

Saudi Code

................................

..50Special Messages

................................

............

Concrete

Design Results

................................

Beam Results

................................

...................

Column Results

................................

................

Concrete Detail Reports

................................

...55Beam Detail Reports

................................

........

Column Detail Reports

................................

.....

Customizing RISA

-2D................................

........

Save as Defaults

................................

..............

Preferences

................................

......................

Design Optimization

................................

..........

Design Lists

................................

......................

Design Rules

–

Size / U.C.

...............................

Design Rules

–

Concrete Rebar

.......................

Table of Contents

RISA

2D v10

Design Rules

Masonry Walls

.........................

Design Rules

Wood Wall (Studs)

...................

Design Rules

Wood Wall (Fasteners)

............

Optimization Procedure

Members

..................

Optimization Procedure

Walls

........................

Optimization Results

................................

........

Drift

................................

......

Drift Results

................................

......................

DXF Files

................................

............................

Importing DXF Files

................................

..........

Exporting DXF Files

................................

.........

Merge After Importing a DXF File

.....................

DXF Element Numbers

................................

....83DXF File Format

................................

...............

Dynamic Analysis

Eigensolution

...................

Required Number of Mo

des

.............................

Dynamic Mass

................................

..................

Solution Method

................................

................

Eigensolution Convergence

.............................

Saving Dynamic Solutions

................................

Work Vectors

................................

....................

Dynamics Modeling Tips

................................

..87Modal Frequency Results

................................

.88Mode Shape Results

................................

........

Dynamics Troubleshooting

–

Local Modes

......

Dynamic Analysis

Response Spectra

...........

Response Spectra

................................

............

Response Spectra Analysis Procedure

............

Frequencies Outside the Spectra

.....................

Mass Participation

................................

............

Modal Combination Option

...............................

Other Options

................................

...................

Localized Modes

................................

...............

RSA Scaling Factor (Manual Scaling)

..............

Automatic Response Spectra Generation

........

Adding and Editing Spectra

..............................

Tripartite Response Spectra

Plot

.....................

Single Spectra Plot

................................

...........

File Operations

................................

...................

Starting Off

................................

........................

Appending Models

................................

............

Importing and Exporting Files

...........................

100

Automatic Backup

................................

.............

100

Generation

................................

..........................

102

Circular Arc Generation

................................

....

102

Circular Radius Generation

..............................

103

Continuous Beam Generation

..........................

103

Grid Member Generation

................................

105

Grid Plate Generation

................................

.......

105

Parabolic Arc Generation

................................

106

Circular Disk Generation

................................

107

General Truss Generation

................................

108

Global Parameters

................................

.............

110

Description

................................

........................

110

Solution

................................

.............................

111

Codes

................................

...............................

112

Concrete

................................

...........................

113

Footings

................................

............................

114

Graphic Display

................................

..................

116

Multiple Windows

................................

..............

116

Controlling the Model View

...............................

116

Depth Effect

................................

......................

118

Viewing Part of the Model

................................

119

Saving and Retrieving Model Views

.................

119

Graphic Display

Plot Options

.........................

120

Joints

................................

120

Members

................................

...........................

121

Plates

................................

122

Panels

................................

...............................

125

Loads

................................

126

Deflection

Diagrams

................................

.........

128

Miscellaneous

................................

...................

129

Graphic Editing

................................

..................

131

Drawing and Modification Features

..................

131

Table of Contents

General Reference Manual

III

Undo Operations

................................

..............

132

Redo Oper

ations

................................

..............

132

Drawing Grid

................................

.....................

132

Snap Points

................................

......................

135

Copying Model Elements

................................

136

Moving and Rotating Model Eleme

nts

.............

139

Scaling Elements

................................

..............

140

Merging Model Elements

................................

141

Deleting Elements

................................

............

141

Graphic Selection

................................

..............

143

Selection Modes

................................

...............

144Inverting Selections

................................

..........

144

Criteria Selections

................................

............

145

Locking Selections

................................

...........

149

Graphic Selection from Spreadsheets

.............

150

Saving Selections

................................

.............

150

Help Options

................................

......................

151

Electronic Help File

................................

..........

151

Context Sensitive Help

................................

.....

151

RISA Technologies Online

...............................

151

Tool-tips

................................

............................

151

Tutorial

................................

..............................

152

Hot Rolled Steel

Databases

............................

153

Hot Rolled Steel

Design

................................

157

Design Parameters Spreadsheet

.....................

157

Member Design Parameters

General

............

158

Member Design Param

eters

AISC Codes

.....

161

Hot Rolled Design Parameters

Canadian

......

162

Hot Rolled Design Parameters

British

...........

163

Hot Rolled Design Parameters

EuroCode

.....

163

Hot Rolled De

sign Parameters

Indian

............

164

General Limitations

................................

..........

164

Limitations

AISC

................................

.............

165

Limitations

Canadian

................................

......

166

Limitations

British

................................

...........

166

Limitations

EuroCode

................................

.....

166

Limitations

Indian

................................

...........

167

Limitations

New Zealand and Australia

..........

167

Special Messages

AISC

................................

167Special Messages

Canadian

..........................

168

Special Messages

Eurocode

..........................

169

Hot Rolled Steel

Design Results

....................

170

AISC Code Check Results

...............................

170

Canadian Code Check Results

........................

171

British Code Check Results

..............................

172

EuroCode Code Check Results

........................

173

Indian Code Check Results

..............................

174

Joints

................................

176

Joint Coordinates Spreadsheet

........................

176

Joint Information Dialog

................................

....

177

Joints

Results

................................

..................

179

Joint Deflections Results

................................

179

Joint Reaction Results

................................

......

179

Joints

Slaving Joints

................................

.......

181

Loads

................................

182

Self Weight (Gravity Load)

...............................

182

Drawing Loads

................................

..................

183

Modifying Loads

................................

...............

183

Deleting Loads

................................

..................

183

Loads

Basic Load Cases

................................

184

Basic Load Case Spreadsheet

.........................

184

Copying Basic Load Cases

..............................

184

Deleting Basic Load Cases

..............................

185

Load Categories

................................

...............

185

Loads

Load Combinations

.............................

187

Load Combinations Spreadsheet

.....................

187

Load Combinations with RSA Results

..............

189

Load Combinations with Moving Loads

............

190

Nesting Load Comb

inations

.............................

190

Transient Load Combinations

...........................

191P-

Delta Load Combinations

..............................

191

Timber Design Load Duration Factor

...............

192

Footing Design Comb

inations

..........................

192

Generating Building Code Combinations

.........

192

Table of Contents

RISA

2D v10

Loads

Joint Load / Displacement

..................

196

Drawing Joint Loads

................................

.........

196

Joint Load Spreadsheet

................................

...

196

Joint Mass

................................

........................

197

Loads

Point Loads

................................

..........

199

Drawing Point Loads

................................

........

199

Point Load Spreadsheet

................................

...

200

Point Load Directions

................................

.......

201

Loads

Distributed Loads

................................

202

Drawing Distributed Loads

...............................

202

Distributed Loads Spreadsheet

........................

203

Distributed Load Direct

ions

..............................

204

Loads

Moving Loads

................................

.......

206

Moving Loads Spreadsheet

..............................

206

Moving Load Patterns

................................

......

207

Moving Loads Procedure

................................

208

Moving Loads Results

................................

......

208

Loads

Thermal Loads

................................

.....

209

Recording Thermal Loads for Members

...........

209

Thermal Force Cal

culation

...............................

210

Prestressing with Thermal Loads

.....................

210

Material Properties

................................

............

Material Properties Spreadsheet

......................

211

Material Take

Off

................................

................

214

Members

................................

.............................

215

Drawing Members

................................

............

215

Modifying Member Properties

..........................

216

Material and Cross Sectio

n Properties

.............

217

Modifying Member Design Parameters

............

218

Splitting Members

................................

.............

219

Members Spreadsheet

Primary Data

.............

220

Members Spreadsheet

Advanced Data

.........

221

Tension/Compression

Only Members

..............

222

Member Information Dialog

..............................

223

Physical Members

................................

............

223

Member Local Axes

................................

..........

224

Defining Member Orientation

...........................

225

Member End Releases

................................

.....

225

Top of Member Offset

................................

.......

226

Member End Offsets

................................

.........

226

Inactive and Excluded Items

.............................

227

Member Shear Deformations

...........................

227

Member Shear Stresses

................................

...

228

Members

Results

................................

.............

229

Number of Reported Sections

..........................

229

Number of Internal Sections

.............................

229

Member Force Results

................................

.....

230

Member Stress Results

................................

....

231

Single Angle Stresses

................................

......

232

Member Deflection Results

..............................

233

Model Merge

................................

.......................

235

Model Merge Options

................................

.......

235

Model Merge Examples

................................

....

236

Model Merge Limitations

................................

236

Model Merge Process

................................

.......

236

Modeling Tips

................................

.....................

239

Applying In

Plane Moment to Plates

................

239

Modeling a Beam Fix

ed to a Shear Wall

..........

239

Modeling a Cable

................................

..............

240

Modeling Inclined Supports

..............................

241

Reactions at Joints with Enf

Displacements

.....

241

Rigid

Links

................................

........................

241

Modeling a "Gap" (Expansion Joint) Between

Structures

................................

.........................

242

P-Delta

Analysis

................................

...............

244

Leaning Column Effect

................................

.....

244P-

Delta Procedure

................................

............

244P-

Delta Limitations

................................

...........

245

Compression Only P

Delta

...............................

245P-

Delta Convergence

................................

.......

245P-

Delta Troubleshooting

................................

...

245

P-Little Delta Analysis

................................

.....

247

P-Little Delta Procedure

................................

...

247

AISC Direct Analysis Method

...........................

248

Table of Contents

General Reference Manual

ACI Concrete Design

................................

........

248

Plate

s/Shells

................................

.......................

249

Drawing Plates

................................

.................

249

Modifying Plates

................................

...............

250

Submeshing Plates

................................

..........

251

Plates Spreadsheet

Primary Data

..................

254

Plates Spreadsheet

Advanced Data

..............

255

Plate Information Dialog

................................

...

255

Plate Corner Releases

................................

.....

256

Inactive and Excluded Plates

...........................

257

Plate Local Axes

................................

...............

257

Plate/Shell Element Formulation

......................

257

Plate Modeling Tips

................................

..........

258

Finite Element Basics

................................

.......

259

Pla

tes/Shells

Results

................................

......

261

Plate Stress Results

................................

.........

261

Plate Force Results

................................

..........

261

Plate Corner Force Results

..............................

262

Plates/Shells

Design Tool

.............................

264

Internal Force Summation Tool

........................

264

Contour Display Details

................................

....

265

Plates/Shells

Modeling Examples

..................

268

Shear Wall Modeling

................................

........

268

Shear Wall Design Forces

................................

269

Shear Wall Penetrations

................................

...

271

Plate Connectivity Problems

............................

271

Mesh Transition Examples

...............................

272

Printing

................................

...............................

273

Printing Reports

................................

................

274

Printing to a File

................................

................

274

Graphics Printing

................................

..............

275

Results

................................

277

Saving Results

................................

..................

277

Results Spreadsheets

................................

......

278

Excluding Results

................................

.............

278

Graphic Results

................................

................

279

Clearing Results

................................

...............

279

Internal Force Summation Tool

........................

279

Member Detail Report

................................

......

279

Concrete Member Detail Reports

.....................

281

RISAFoot Integration

Design

..........................

282

Design Procedure for Integrating RISAFoot and

RISA

-2D................................

............................

282

Footing Geometry

................................

.............

282

Footing Pedestal

................................

...............

283

Soil Properties

................................

..................

283

Local Axes

................................

........................

284

Limitations

................................

.........................

285

RISAFoot Integration

Footing Results

..........

286

Solution Methodology

................................

.......

286

Sketch and Details

................................

............

286

Soil Bearing Results

................................

.........

287

Footing Flexure Design

................................

....

288

Footing Shear Check

................................

........

289

Pedestal Design

................................

...............

290

Stability Results

................................

................

291

Concrete Bearing Check

................................

292

Footing Stability and O

Calculations

.............

293

Calculation of OTM Stability Ratio

....................

293

Calculation of Moment and Shear Demand for

Unstable Footings

................................

.............

294

Limitation on Optimization for Net Uplift

...........

295

Section Set

................................

.......................

296

Section Sets Spreadsheet

................................

296

Shape Databases

................................

...............

298

Database Shape Types

................................

....

298

Hot Rolled Shapes

................................

............

298

Cold Formed Shapes

................................

........

298

Concrete Shapes

................................

..............

298

Wood Shapes

................................

...................

298

General Shapes

................................

................

298

Database Files

................................

..................

301

Solution

................................

...............................

302

Static Solutions

................................

.................

302

Dynamic Solutions

................................

............

303

Table of Contents

RISA

2D v10

Response Spectra Solutions

............................

303

Spreadsheet Operations

................................

...

304

Moving and Scrolling

................................

........

304

Spreadsheet Keyboard Commands

.................

304

Selecting Spreadsheet Cells

............................

305

Undoing Operations

................................

.........

305

Redoing Operations

................................

.........

305

Editing Spreadsheets

................................

.......

305

Moving and Copying Cell Contents

..................

307

Sorting and Finding in Spreadsheets

...............

308

Default Spreadsheet Data

................................

308

Special Spreadsheet Functions

........................

308

Stability

................................

...............................

310

Instability Procedure

................................

.........

310

Instability Causes

................................

.............

310

Instability Examples

................................

..........

311

Testing Instabilities

................................

...........

313

Units

................................

....

315

tandard Imperial Units

................................

....

315

Standard Metric Units

................................

.......

315

Units Specifications

................................

..........

316

Wall Panels

................................

.........................

317

Drawing Wall Panels

................................

........

317

Modifying Wall Panels

................................

......

318

Wall Panel Spreadsheets

................................

320

Wall Panel Editor

................................

..............

321

Load Attribution

................................

................

323

Meshing the Wall Panels

................................

324

Wall Panels

Results

................................

.........

331

Masonry Wall Panel

Design

............................

333

Masonry Wall Input

................................

...........

333

Masonry Wall Optimization

...............................

337

Masonry Wall Results

................................

........

338

Masonry Wall Spreadsheet Results

.................

338

Concrete Reinforcing Spreadsheet Results

.....

338

Masonry Wall Detail Reports

............................

339

Masonry Detail Reports

Lintels

......................

344

Wood Wall

Design

................................

...........

347

Wood Wall Input

................................

...............

347

General Requirements for Shear Walls

............

349

General Program Functionality and Limit

.......

354

Wood Wall Results

................................

.............

362

Wood Wall Results Spreadsheets

....................

362

Wood Wall Self Weight

................................

.....

363

Wood Wall Detail Reports

................................

363

Warning Log

................................

.......................

375

Wood

Database

................................

................

Custom Wood Sizes

................................

.........

378

Wood

Design

................................

....................

379

Glu-Lams

................................

..........................

379

Custom Wood Materials & Structural Composite

Lumber

................................

..............................

379

Wood Member Design Parameters

..................

380

Timber Design Adjustment Factors

..................

382

Wood Member Code Check Results

................

384

Special Messages

Wood

Design

....................

385

Limitations

Wood Design

................................

385

Appendix A

–

Redesign Lists

...........................

387

Appendix B

–

Error Messages

..........................

389

Appendix E

Interfacing

w/Other Programs

390

Integration with other RISA programs

..............

390

Importing or Exporting DXF Files

.....................

390

Structural Desktop

................................

............

390

Appendix F

–

Wood Shear Wall Files

...............

391

Hold Downs

................................

......................

391

Panel Nailing Schedules

................................

...

392

Technical Support

................................

..............

394

Before You Begin

General Reference Manual

Before You Begin

Welcome to the RISA

-2DGeneral Reference manual

. Please read this topic

prior to installing the program

and pay particular

attention to the

License Agreement

If you agree to the terms of the license th

en read the

Installation

section and install the

program.

If you are a first time user of RISA

2D you should turn your attention to the

User's Guide

(a separate document)

which is designed to get you up and running as fast as p

ossible while still exposing you to the important features of the

software.

The

User's Guide

is designed to be read in two ways. If you are already familiar with structural modeling in general you can

skip the supporting text and read only the

underlined a

ction items

to quickly move through the tutorial. If you want more

thorough explanations of the modeling process you may read all or some of the supporting text as you see fit.

After you have gone through the

User's Guide

, use this

General Reference

for de

tailed information on any topic. The topics

are arranged in alphabetical order and are thoroughly indexed.

Overview

RISA

2D is a general

purpose

2-dimensional analysis and design program. This program has been developed to make the

definit

ion, solution and modification of

structural models as fast and easy as possible. Analysis, up to and including

calculation of maximum deflections and stresses, may be done on structures constructed of any material or combination of

materials. Complete

steel and wood design are also included in the program.

RISA

2D has full graphical modeling capability. You can draw your model on the screen and also perform extensive

graphical editing simultaneously in multiple views. To modify your model data directly,

RISA

-2Demploys a powerful,

proprietary spreadsheet. All this combined with flexible data generation algorithms makes modeling very easy. Graphic

display of the model along with applied loads, boundary conditions and much more, is always available. The m

odel can be

rapidly edited, solved, viewed, modified, re

solved, etc. The truly interactive nature of RISA

-2Dis its primary strength.

RISA

2D is also able to perform elaborate error checking as you define the model, and offers context sensitive help ever

step of the way.

RISA

2D is an

interactive

program as opposed to a

batch

mode program. With a batch mode program, you would edit a text

file in one program (typically called a pre

processor), and then solve it with another program, and then view the solu

tion

results in yet another program (typically called a post

processor). With RISA

2D, all model editing, model solution, and

results browsing is accomplished through the same interface and with the same program. The interactive approach offers

several uni

que advantages over batch mode which include; the ability to do real time error checking of your model data, the

ability to do rapid model editing, solution, editing, and re

solution without jumping from one program to another, and the

need for the user to

learn only one program interface.

You may access the features in RISA

2D by using the menu system, or the toolbars. The best way to learn RISA

-2Dis to go

through the

User's Guide

. The advantage to this is that you are exposed to the tools RISA

2D provide

AND

the ways that

you can take advantage of them.

Hardware Requirements

Minimum



Any Windows compatible computer with a Pentium 3 or better processor



Windows 2000

\XP\

Vista

Windows 7



256 MB of RAM



00 MB of hard disk space



Two or three button mouse



USB port (required for Stand

Alone version or the Network Host computer)

Before You Begin

RISA

2D v10

Recommended



Windows XP

Vista

Windows 7



256MB of RAM



200MB of hard disk space



Two button mouse with wheel

Note



The amount of space ne

eded by RISA

-2Dto solve a particular structural model depends on the size of the model.

RISA

-2Dhas been written such that it will use as much RAM as is available. If this isn't enough, RISA

2Dn will

start using HD space until enough memory is obtained

to solve the problem. Of course, if RISA

2D is required to

use HD space, the solution will be much slower. So, the more memory you have available, the better. In general,

256

Megabytes (MB) of RAM is a good amount to solve most problems. However, if you wi

ll be regularly

solving large problems, more memory will save you a lot of time in the long run.

Program Limits

1,000 Joints

1,000 Members

1,000 Plates

5,000 Section Sets

500 Materials

500 Custom Wood Species

1,000 Ba

sic Load Cases

10,000 Loads

1,000 Moving Loads

1,000 Load Combinations

500 Mode Shapes

Demonstration Version:

While you can open and solve a larger model, the largest model that can be saved to disk with the

demonstration version is limited to

20 Joints, 2

0 Members, 20 Plates and 1 wall panel

License Agreement

END

USER LICENSE AGREEMENT FOR RISA Technologies, LLC® SOFTWARE

The RISA

2D software product (SOFTWARE PRODUCT) includes computer software, the associated media, any printed

materials, and any electronic documentation.

By installing, copying or otherwise using the SOFTWARE PRODUCT, you

agree to be bound by the terms of this agreement.

If you do not agree with the terms of this agreement RISA Technologies,

LLC is unwilling to

license the SOFTWARE PRODUCT to you.

In such event you must delete any installations and destroy

any copies of the SOFTWARE PRODUCT and return the SOFTWARE PRODUCT to RISA Technologies, LLC within 60

days of purchase for a full refund.

The SOFTWARE PRODUCT is protected by United

States copyright laws and various international treaties.

All rights not specifically granted under this agreement are reserved

by RISA TECHNOLOGIES.

1. SOFTWARE LICENSE

The SOFTWARE PRODUCT is licensed, not sold.

All right, title and interest is and remains

vested in RISA Technologies, LLC.

You may not rent, lease, or lend the SOFTWARE PRODUCT.

You are specifically

granted a license to the use of this program on no mor

e than one CPU at any given time.

The Network Version of the

Before You Begin

General Refe

rence Manual

SOFTWARE PRODUCT is licensed for simultaneous use on a certain maximum number of network stations that varies on a

per license basis. As part of the license to use the SOFTWARE PRODUCT, the progr

am user acknowledges the reading,

understanding and acceptance of all terms of this agreement.

The SOFTWARE PRODUCT may not be reviewed, compared

or evaluated in any manner in any publication without expressed written consent of RISA Technologies, LLC.

u may not

disassemble, decompile, reverse engineer or modify in any way the SOFTWARE PRODUCT. If the SOFTWARE

PRODUCT was purchased at a discounted price for educational purposes it may in no event be used for professional design

purposes.

The terms of thi

s license agreement are binding in perpetuity.

2. DISCLAIMER.

We intend that the information contained in the SOFTWARE PRODUCT be accurate and reliable, but it

is entirely the responsibility of the program user to verify the accuracy and applicability of a

ny results obtained from the

SOFTWARE PRODUCT.

The SOFTWARE PRODUCT is intended for use by professional engineers and architects who

possess an understanding of structural mechanics.

In no event will RISA Technologies, LLC or its officers be liable to

anyo

ne for any damages, including any lost profits, lost savings or lost data. In no event will RISA Technologies, LLC or its

officers be liable for incidental, special, punitive or consequential damages or professional malpractice arising out of or i

connect

ion with the usage of the SOFTWARE PRODUCT, even if RISA Technologies, LLC or its officers have been

advised of or should be aware of the possibility of such damages.

RISA TECHNOLOGIES' entire liability shall be limited to

the purchase price of the SOFTWAR

E PRODUCT.

3. LIMITED WARRANTY.

RISA Technologies, LLC warrants that the SOFTWARE PRODUCT will operate but does not

warrant that the SOFTWARE PRODUCT will operate error free or without interruption.

RISA Technologies sole obligation

and your exclusive reme

dy under this warranty will be to receive software support from RISA Technologies via telephone,

email or fax. RISA Technologies shall only be obligated to provide support for the most recent version of the SOFTWARE

PRODUCT. If your version of the SOFTWARE

PRODUCT is not the most recent version RISA Technologies shall have no

obligation to provide support in any form. Except as stated above the SOFTWARE PRODUCT is provided without warranty,

express or implied, including without limitation the implied warran

ties of merchantability and fitness for a particular purpose.

4. PROTECTION DEVICE.

In the event the SOFTWARE PRODUCT requires the use of a PROTECTION DEVICE to

operate, you are specifically prohibited from attempting to bypass the functionality of the P

ROTECTION DEVICE by any

means. If the PROTECTION DEVICE becomes broken or inoperable it should be returned to RISA TECHNOLOGIES for a

replacement. The replacement will not be provided if RISA TECHNOLOGIES can not affirm that the broken PROTECTION

DEVICE wa

s originally provided by RISA TECHNOLOGIES for use with the SOFTWARE PRODUCT. A lost or stolen

PROTECTION DEVICE will not be replaced by RISA TECHNOLOGIES.

5. TERMINATION.

RISA TECHNOLOGIES may terminate your right to use the SOFTWARE PRODUCT if you fail t

comply with the terms and conditions of this agreement.

In such event you must delete any installations and destroy any

copies of the SOFTWARE PRODUCT and promptly return the SOFTWARE PRODUCT to RISA Technologies.

6. CHOICE OF LAW.

By entering into this

Agreement in accordance with Paragraph 1, above, you have agreed to the

exclusive jurisdiction of the State and Federal courts of the State of California, USA for resolution of any dispute you have

relating to the SOFTWARE PRODUCT or related goods and ser

vices provided by RISA Technologies. All disputes therefore

shall be resolved in accordance with the laws of the State of California, USA and all parties to this Agreement expressly

agree to exclusive jurisdiction within the State of California, USA. No ch

oice of law rules of any jurisdiction apply.

"RISA" as applied to structural engineering software is a trademark of RISA Technologies.

Maintenance

Program maintenance

provides all

upgrades

to RISA

-2D, and discounts on new products.

When your maintenance expires, you will be given the opportunity to continue program maintenance on an annual basis. You

are under no obligation to continue program maintenance, of course, but if you decide to discontinu

e maintenance you will

no longer receive RISA

2D program upgrades and technical support.

Complete program support is available to registered owners of

RISA

-2Dand is included in the purchase price. This support is

provided for the life of the program. See

Technical Support

for a list of your support options.

The “life of the program” is defined as the time period for which that version of the program is the current version. In othe

words, whenever a new version of RISA

-2Dis

released, the life of the previous version is considered to be ended.

RISA Technologies will support only the current version of

RISA

-2D.

Before You Begin

RISA

2D v10

Installation

To install RISA

-2Dplease follow these instructions:

Put the RISA

2D CD in your com

puter CD drive.

If the CD starts automatically go to step 4. If the CD does not start after 10 seconds click the Windows

Start

button

and select

Run

.3.In the Run dialog box type “

d:\launch

” (where “d” is the label of your CD drive) and then click the

but

ton.4.Follow the on

screen instructions.

Application Interface

General Reference Man

ual

Application Interface

The

User's Guide

(a separate document) contains a tutorial that leads you through the RISA

-2Dinterface with an actual

model. Consider going thro

ugh the tutorial if you have not done so already, as it is the fastest way to learn the program.

Although it requires some time up front, the tutorial will save you time and brainpower in the long run.

The features that are available to you in RISA

-2Dmay

be accessed through the main menu, shortcut menus, toolbars and

shortcut keystrokes. You may use any or all of these vehicles to interact with the software. The main menu has the advantage

of containing all of the program options and features and may initi

ally be the simplest to use, letting you learn just one

system. The toolbars contain more common options and invoke with one click. The shortcut menus present options relevant

to the task at hand. The shortcut keys provide a fast way to access features sho

uld you use the program often enough to make

them familiar to you. All of these features are discussed in the sections below. There are many ways to access features and

the method that you will use will simply be a matter of personal preference. The good n

ews is that you have the options.

The bar along the top of the screen is called the titlebar and contains the name of the file that is currently open. The thre

buttons

n the far right side of the title bar are used to control the main window. The left button will shrink the

main application window to a button on the taskbar. The middle button will shrink or maximize the window on your screen.

The right button will close

the window, prompting you to save changes if necessary. You will also see these buttons in other

windows and they have basically the same functions there as well.

The actual work that you do will be in the main area on the screen, which is called the works

pace. When you open a model

view, a spreadsheet or a dialog it will be opened in the workspace and listed in the

Window

menu. You may have as many

windows open as you like.

Main Menu

All of the program features may be accessed through the main menu system at the top of the screen beginning with

File

the far left and ending with

Help

on the far right.

Clicking on each of these menus (listed below) will display sub

menus that

conta

in options that you may choose from. You may also select the main menus by using the ALT key along with the

underlined letter in the menu you wish to choose. You may then continue to use the keyboard to choose from the menu

options. In addition, some of th

e menu options will have hot key combinations listed to the right of the option. These hot keys

allow you to use the keyboard to access features without using the menu system.

File Menu

New

will close t

he current file, prompting for saving if necessary, and will open a new file.

Open

will close the current file, prompting for saving if necessary, and will open an existing file.

Save

will save the current file, prompting for a name if necessary.

Save As

ill save the current file, prompting for a name.

Append

will insert another RISA

-2Dmodel into the current model.

Import

will

close the current file, prompting for saving if necessary, and will open an existing DXF file.

Export

will export the current file

to a DXF

, SDNF, or Pro

Steel exchange

file.

For more information on the interaction between RISA and other programs refer to

Appendix E.

will access RISA

-2Dprinting options.

Page Setup

will present page setup optio

ns for printing.

Recent Files

The five most recent files will be listed at the bottom of the menu. Selecting one of these files will close the

current file, prompting for saving if necessary, and will open the selected file.

Exit

will close RISA

-2D, prompt

ing for saving if necessary.

Application Interface

RISA

2D v10

Edit Menu

Undo

will undo the last edit that was applied to the model whether it was made graphically or in the spreadsheets. You may

continue

to apply Undo to remove up to 100 model edits.

Redo

will reverse the last undo that was applied to the model. You may continue to apply Redo to remove up to 100 undo

operations.

Copy

will copy the selected spreadsheet cells or model view from the active w

indow to the clipboard.

Paste

will paste data from the clipboard to the spreadsheet cells.

Insert Line

will insert a new line in the spreadsheet beneath the current line.

Delete Line

will delete the current spreadsheet line.

Repeat Line

will insert a new l

ine in the spreadsheet beneath the current line and copy the data from the current line.

Mark All Lines

will select all of the lines in the spreadsheet.

Unmark Lines

will unmark any currently marked lines.

Delete Marked Lines

will delete the marked lines i

n the spreadsheet.

Find

will locate an item on the spreadsheet by its label.

Sort

will sort the column containing the active cell.

Fill Block

will fill the marked block of cells with a valid entry.

Math on Block

allows you to add, subtract, multiply or div

ide the values in the marked block of cells.

Global

opens the Global Parameters for the model.

Units

opens the Units settings.

View Menu

New View

will open a new model view window.

Save or Recall Views

allows you to save a view or recall a view that has previously been saved.

Clone View

makes a copy of the current view so you can modify one and maintain the other.

Refresh All

will refresh all of the windows that are open in the workspace.

Select

provides

graphic select options that are also provided on the

Selection Toolbar

Unselect

provides graphic unselect options that are also provided on the

Selection Toolbar

Save or Recall Selection States

allows you to save a selection or recall a selection that h

as previously been saved.

Zoom

provides options for zooming in and out of the current model view.

Rotate

provides options to snap the model view to global planes or an isometric

view.

Plot Options

opens the Plot Options.

Render

will turn rendering of the c

urrent model view on or off, depending on the current setting.

Drawing Grid

will turn the display of the Drawing Grid on or off, depending on the current setting.

Axes

will turn the display of the global axes in the model view on or off, depending on the c

urrent setting.

Boundaries

will turn the display of the boundary conditions on or off, depending on the current setting.

Application Interface

General Reference Man

ual

Loads

will turn the display of the model loads on or off, depending on the current setting.

Joint

Labels

will turn the display of the

oint

labels on or off, depending on the current setting. A third setting is also

available where the

joints

themselves are not shown at all.

Member

Labels

will turn the display of the

member

labels on or off, depending on the current setting. However, if r

endering

is turned on,

member

labels will not be visible in the model view.

Insert Menu

The

Insert Menu

will help you insert new items into the model. Most of the options will provide a graphical method of

insertion but some will open s

preadsheets where appropriate. See

Graphic Editing

for specific information.

Modify Menu

The

Modify Menu

will help you modify existing items in the model. Most of the options will provide a graphical meth

od of

modification but some will open spreadsheets where appropriate. The

Delete Items Dialog

may also be accessed via this

menu. See

Graphic Editing

for specific information.

Spreadsheets Menu

The

Spreadsheets Menu

provides access to any of the input spreadsheets. See

Spreadsheet Operations

to learn how to work

within the spreadsheets.

Solve Menu

Clicking on the

Solve Menu

will immediately begin a s

olution to the model. See

Solution

for more information.

Results Menu

The Results Menu provides access to any of the results spreadsheets. See

Results Spreadsheets

for more in

formation.

Tools Menu

Relabel Joints

assigns new labels to the joints in their current order in the

Joint Coordinates

spreadsheet.

Relabel Members

assigns new labels to the members in their current order in the

Members

spreadsheet.

Relab

el Plates

assigns new labels to the plates in their current order in the Plates spreadsheet.

Full Model Merge

will merge

the entire model.

See

Model Merge

for more information.

Align Wall Panel

will perform a merge of the

wall panels to make sure they are lined up in the vertical direction. Use this

utility if you are receiving wall panel errors at solution.

Round off joint coordinates

will round off the coordinates.

Switch Vertical Axes

allows you to switch your vertical a

xis while maintaining consistent member orientation.

Preferences

contain settings that let you customize the program. See

Customizing RISA

for more information.

Customize Toolbar...

allows you to modify the model view toolba

r by adding, subtracting and re

ordering buttons. See the

customizable toolbar

section.

Reset All Program Defaults

will reset all customized settings to the original factory settings.

Window Menu

In order to help you work with t

he model and the results, you are provided with many window arrangements to choose from.

You may access them from the

Window Menu

. The best way to understand just what these 'tilings' do is to try them.

Application Interface

RISA

2D v10

Remember that once you choose a tiling you may adjust

any of the windows as you wish.

You may also use the

Tile

button on the

RISA Toolbar

to access a list of tilings.

Help Menu

Help Topic

opens the RISA

-2DHelp File so that you may search the contents and the index. See

Help Options

to learn

about getting help.

Check for Updates

runs an internal check for possible program updates. If your program is up to

date, you will receive a

message saying you are up to date. If you are out of date, the check will offer you the option to email RISA Technologies for

upgrade information if you are out of date for a major update. If you are out of date just a minor update

, then we will send

you to our website to upgrade.. This check is also offered during the installation process.

About

provides RISA

-2Dversion and hardware key information.

Short

cut Menu

The

Shortcut Menu

is also referred to as the

Right

Click Menu

. This is because to access the shortcut menu you simply

click the RIGHT mouse button where you are working to see options that are relevan

t to what you are doing. For example if

you are working in a model view the right click menu will provide options to help you modify the view and edit the model

graphically. If you are working in a spreadsheet the menu will provide editing tools for that s

preadsheet.

This menu will appear wherever you RIGHT click the mouse. This way you do not need to move away from where you are

working to select the features you want to use.

Toolbars

The

Toolbars

provide buttons to help you access common

commands and popular options in the menu system discussed

above. There are different toolbars that will appear as you work to build your model and browse your results. If at any time

you are not sure what a particular button does, simply let your mouse hov

er over the button and a helpful tip will pop up and

explain the button.

RISA Toolbar

The first horizontal toolbar located just below the Main Menu is called the

RISA Toolbar.

The buttons on this bar facilitate

file and window access. You may use these buttons to open files and windows and

also to analyze the model.

Window Toolbar

The

Window Toolbar

is the second horizontal toolbar located below the Main Menu. It gets its name because the buttons

change as you move from window to window in order to help you with what you are currently doing. When

you are working

in a model view the buttons provide viewing tools, such as

Rotate

and

Zoom

, to assist you with that view. There are also

many other results and information display toggles, including some icons with the drop down arrow next to them. Clickin

the arrow will show you the different view options for that icon. Clicking the icon itself will bring you back to the default

view. Note that this model view toolbar is now fully customizable. See below for more information.

Other model view windows that

are open will not be affected so that each may show different information. When you are

working in a spreadsheet, editing tools are provided that are appropriate to that particular spreadsheet. Note that not all t

ools

are available with all spreadsheets.

In fact there are many tools that are provided for one spreadsheet only. See

Spreadsheet

Operations

for more information.

Application Interface

General Reference Man

ual

Customizable Model View Toolbar

The model view toolbar is full

y customizable. By creating your personalized toolbar, you can quickly access your most

frequently used buttons. This can be done quickly and easily in just a few steps.

Go to Tools menu and select Customize Toolbar.

Select one of the toolbars by clicking in the box Available toolbar buttons, and click on Add to place them on the

current toolbar.

Once you’ve moved the buttons to the Current Toolbar, you can rearrange them by clicking on Move Up or Move

Down.

Application Interface

RISA

2D v10

Click Close and you will see your se

lections on the model view toolbar.

Note:



You must have a model view as the current view to see this toolbar.



If you add more buttons than will fit on the toolbar the buttons that are at the end of the "Current toolbar buttons" will

be cut off.



The changes

you have made will automatically be saved on a per

user (Windows User) basis, such that next time you

open the program the toolbar will be arranged per your preferences.

Selection Toolbar

The vertical toolbar on

the left side of the screen is the

Selection Toolbar.

This toolbar will only be available when the active

window is a model view. The buttons on this toolbar help you select and unselect items in the model in order to help you

build and modify the model o

r view results. See

Graphic Selection

for more information.

Drawing Toolbar

Another toolbar that is available is the

Drawing To

olbar

Unlike those mentioned above, this toolbar is located in the model

view windows rather than in the main application window. This way the drawing tools stay close to where you are working.

This toolbar controls modeling features that help you draw, l

oad, and modify your model graphically. You may have more

than one view open and a Drawing Toolbar for each view.

This way you can simultaneously draw plates in one window and

members in another.

The

Drawing Toolbar

may be displayed in any model view windo

w by clicking

on the

Window Toolbar

while in the

model view window. Some of the buttons on the toolbar are for one

time applications such as modifying the

drawing grid.

Other buttons place you in an editing mode, such as Draw

Members

, that remains active until you cancel it. The current mode

is indicated by the mouse pointer and by the state of the button. While in an editing mode the button will stay down u

ntil you

click it again or choose another button. See

Graphic Editing

for more information.

This brings us to an important point. Some of the toolbar buttons remain down when you press them to indicate that you are

in a cert

ain mode or that something is either on or off. For example the

Box Zoom

button will stay down to indicate that

you are currently in the zooming mode. The

Show Drawing Toolbar

button will remain down when you turn on this

Application Interface

General Reference Man

ual11toolbar for the active window. You may be in more than one mode at the same time as long

as they are not mutually

exclusive.

The

Data Entry Too

lbar

is the vertical toolbar on the right side of the application window. It contains buttons that facilitate

data entry through the spreadsheets. The buttons on this toolbar provide quick access to the spreadsheets that are also

listed in

the

Spreadsheets Menu

. You may open and close the toolbar by clicking the

button on the

RISA Toolbar.

The

Results Toolbar

is the vertical toolbar on the right side of the application window that is placed over the

Data Entry

Toolbar

after the model has been solved. The buttons on this toolbar provide quick access to the results spreadsheets that are

also listed in the

Resul

ts Menu

. You may open and close the toolbar by clicking the

button on the

RISA Toolbar.

Dynamic View Controls

When your current window is a graphical model view, you can use the mouse wheel to dynamically zoom, pan, or rotate the

graphical image.

These functions are only available to users who have a mouse with a wheel button and whose co

mputers are

running the Windows XP operating system.

Mouse Action

Model View Function

Rolling the Wheel

Forward

Zoom In

Rolling the Wheel

Backward

Zoom Out

Clicking and holding the

Wheel Button

Grab the image and pan in the direction of

mouse movement

Click and hold the Wheel

button while pressing the

Shift key

Dynamically rotate the structure in the

direction of mouse movement

Dynamic Pan

: Clicking and holding the mouse wheel button triggers the tool and allows the user to pan or drag the view to

e limit of scroll bars.

Dynamic Zoom

: This tool uses the wheel button on the mouse. Rotating forward zooms in and rotating backward zooms out.

Dynamic Rotate

: This tool is triggered by clicking and holding the mouse wheel button while holding the Shift key

. The

rotational movement will be based on the how the user drags the mouse cursor over the screen and the projection of global

axis on the screen. For rotation about X axis, drag the cursor perpendicular to the projection of the global X axis. The same

gic applies for Y or Z axis rotations. When rotation is initiated, the system locks for rotation about that axis until the us

releases the middle mouse button.

Application Interface

RISA

2D v10

Zoom Previous/Next

: Function keys F3 and F4 are associated with Zoom Previous and Zoom Next re

spectively. The system

holds a doubly linked list of zoom info. This list has 10 zoom

states in the list. The F3 or F4 keystroke moves the active

pointer forward or backward on the list. Each window has its own zoom list.

Dynamic Dist

ance Tool

: This tool triggers by pressing the F5 key. The user has to pick up two points on the screen and the

system gives back the total and partial distance between points on the status bar.

Shortcut Keys and Hot Keys

Shortcut Keys

and

Hot Keys

allow you to use the keyboard to quickly access features. The difference between the two is

simply that the shortcut keys are related to a specific window and will only work in

that window while the hot keys will

perform at most any time.

General Hot Keys

Key Combination

Function

Help on the active window

Activates the Dynamic Distance Tool

Ctrl-F1

Main Help topics

Ctrl-F2

Create New view

F7, Ctrl

-F7Opens solution choices

Ctrl-Alt-F7

Replace shapes with suggested shapes and

re-solve the model

Ctrl-C

Copy to the clipboard

Ctrl-V

Paste from clipboard

Ctrl-N

Start a new file

Ctrl-O

Open an existing file

Ctrl-S

Save the current file

Ctrl-P

PrintCtrl-Z

Undo

Alt-Access the menus by combining the Alt

key with the underlined letter in the menu

Shortcut Keys available for Specific Windows

Key Combination

Model View Window

Spreadsheet

Ctrl-D

Open last graphic editing

dialog

Delete Marked Lines

Ctrl-G

Toggle Drawing Toolbar

Ctrl-A

Select All

Ctrl-U

Unselect all

Ctrl-F

Block Fill

Ctrl-M

Block Math

Ctrl-I

Invert Selection

Application Interface

General Reference Man

ual13Ctrl-L

Toggle Lock unselected

Unmark lines

Ctrl-Enter

Press cell

button

Open Plot Options

Start/Stop Cell Edit

Zoom Previous

Insert line

Zoom Next

Delete Line

Initiates the "Distance" tool

FindF8Repeat Current Line

Sort+Zoom In

-Zoom Out



PgUp PgDwn

Scrolling

Spreadsheet Hot Keys that open spreadsheets

Key Combination

Unsolved model

Solved Model

Ctrl-Alt-B

Basic Load cases

Ctrl-Alt-C

Joint

Coordinates

Corner Forces

Ctrl-Alt-D

Distributed

Loads

Joint Displac

ements

Ctrl-Alt-E

Members

–

Primary Data

Member

Ctrl-Alt-F

Member Forces

Ctrl-Alt-G

Global Parameters

Ctrl-Alt-H

Model Generation

Suggested Shapes

Ctrl-Alt-L

Load Combinations

Plate Forces

Ctrl-Alt-M

Materials

Material Take Off

Ctrl-Alt-N

Joi

nt Loads

Concrete Reinforcing

Ctrl-Alt-O

Boundary Conditions

Mode Shapes

Ctrl-Alt-P

Member

Point Loads

Plate Stresses

Ctrl-Alt-Q

Frequencies

Ctrl-Alt-R

Design Rules

Reactions

Ctrl-Alt-S

Section Sets

Member Stresses

Ctrl-Alt-T

Story Drift

Ctrl-Alt-UDesign Results

Ctrl-Alt-V

Moving Loads

Ctrl-Alt-X

Surface Loads

Ctrl-Alt-Y

Dynamics Settings

Ctrl-Alt-4

Plates

Application Interface

RISA

2D v10

Status Bar

The

Status Bar

passes useful information to you as you work. It is divided into four parts located along the very bottom of

the mai

n application window, just beneath the workspace.

The left side of the status bar shows a solution flag to indicate the solved state of the model as follows:

Solution Type

Unsolved

Solved

Static

Dynamic

Response Spectra

To the right of the solution flags there are three message boxes.

The first and largest box lets you know what you are currently doing. If you are in a spreadsheet, this box will contain the

xplanation of the current cell. If you are working in a model view and select a graphic editing option, look to this box for

information on how to use the feature.

The second box is used to pass you units of the current spreadsheet cell.

The third box indi

cates the coordinates

of the mouse when a model view is active. The mouse coordinates that are displayed

are the coordinates of the grid point or joint that is nearest to the mouse.

Windows

Modeling the structure will take place within mode

l views and spreadsheets, each in their own window that may be moved

around the workspace

and sized as you wish. The ability to have multiple model views and multiple spreadsheets open at one

time is a powerful feature. The options in the

Window Menu

are p

rovided to help you manage these windows.

These windows contain three buttons

in the upper right corner to help you minimize, maximize and close the

window, respectivel

y. There are also scroll boxes to help you view information that is outside of the window viewing area.

Click the scroll bar buttons or drag the scroll box to advance the display in one direction or another.

Model Views

Model View

window

s show a graphic view of the model. Open a new view with the

button.

You may open as many model view windows as you like. This is especially helpful when

working in close on large models.

You might have one overall view and a few views zoomed in and rotated to where you are currently working. You may also

have different information plotted in multiple views.

One thing to remember is that the toolbars that

are displayed depends upon what window is active. The active window is the

one with the blue titlebar. For example, if you are looking for the zoom toolbar button and the active window is a spreadshee

you need to select a model view first before you can a

ccess the zooming tools.

Spreadsheets

Spreadsheet

windows are made up of rows and columns of data cells. If you wish to add or edit data in a spreadsheet cell

you click on the cell, making it the active cell, and then edit the cell. This active cell is sim

ply the green cell that moves

around the spreadsheet as you hit the cursor keys (

← , →

), Page Up, Page Down, Home, End, etc. There is always one and

only one active cell, which is the cell that has the

“

attention

”

of the keyboard.

You may also select blocks of data to work on. You can select a block of data by clicking and holding the

mouse button on

the first cell in the block and then dragging the mouse to the opposite corner of the block and releasing the mouse.

Application Interface

General Reference Man

ual

Dialogs

Dialog

is a third type of window and is used to access a specific function within the progra

m. Another powerful feature is

that most of the dialogs may be left open while you edit the model, making it easy to make adjustments as you work. You

will find that dialogs are very easy to work with. There are

Help

buttons that will bring you directly to

the relevant topic in

the help file.

You may also click on the

button in the titlebar, and then click on any item in the dialog to get help for that

ite

Window Tiling

Standard window tilings help you set up your workspace. Select the

Tile

button and then select a ti

ling or choose

them from the

Window

Special Tiling

menu.

The standard tilings include arrangements of spreadsheets and model view windows for creation of mod

els and viewing

results. Each of these groups have arrangements for working with joints, members, and plates and also loads. The best way to

learn what these tilings do is to try them.

Modes

There are three basic program modes

(

View, Select,

and

Edit

) and a mode hierarchy to allow you to move between them

easily. While you are

editing

the model you may

select

items to edit. When you a

re finished

selecting

you will be returned to

editing

. Likewise, while you are

selecting

items you can adjust the

view

and then be returned to

selecting

Different mouse cursors are used with each mode to make it clear what the current mode is.

View Mode

s the upper level mode that allows you to adjust the view by zooming in and out, rotating and setting plot

options. This mode supersedes all other modes so that you may do these things at any time, and then be returned to the

previous mode. This mode does

not cancel other modes so that when you are finished adjusting the view you are returned to

what you were doing. See

Graphic Display

for more information.

Select Mode

is the middle level mode that allows you to make a graphi

c selection of joints, members and plates.

This mode

supersedes the

Edit Mode

but not the

View Mode

. This means that you can make a selection while in the middle of editing

the view and when you are finished you are returned to the editing feature that yo

u were using. It also means that you may

adjust the view while remaining in the same

Select Mode

. See

Graphic Selection

for more information.

Edit Mode

is the lower level mode that allows you to graphically edit the model.

You may make selections and adjust the

view while in the edit mode such that when you are finished selecting you will be returned to the

Edit Mode

Some

Edit

Mode

features have options on how you apply the edit. See

Graphic

Editing

for more information.

Note



The default mode

is the mode you are in if you are not in any other mode and is indicated by the standard

mouse cursor.

The default mode is a selection mode where you can select/unselect individual items by clicking

on them.

You may also double

click on an item to view information about the item.



You may use the ESC key or the right mouse button to cancel a mode.

Aluminum

Database

General Reference Manual

Aluminum

Databases

Shapes are organized in the database by country.

The shapes available are from the ADM 2005 Section Properties section.

You may type in the names directly, select shapes from these

databases or add your own shapes.

RISA currently supports the following common Cold Formed steel databases: Aluminum US, and Aluminum CAN.

To Select a Cold Formed Database Sh

ape

From the

Aluminum

Section Sets

tab on the

Spreadsheet

, or the

Primary

tab of the

Members Spreadsheet

move

the cursor to the

Shape

field and click

.2.Specify the

database and shape type you wish to use and then select from the list of available shapes by clicking on

Database Files

The aluminum shape databases are

stored in the files ADMdbUS32.fil and ADMdbCAN32.fil.

Aluminum

Database

General Reference Manual

To Add a Database Shape

On the

RISA Toolbar

click the

Edit Shape Database

button.

Select the Aluminum tab, then select the shape type you wish to add and click the

Add

button.

Specify a name for the shape and fill in the

Basic Properties.

Click

Calc Props

to de

termine the shape properties.

Note



Alterations to the shape database are not permanent unless you agree to save them.

Changes that are not saved

only remain valid for the current session and will not be present the next time you start RISA.



New shapes are

added to the bottom of the database.



To delete a shape, specify the database and shape type you wish to delete and then click the

Delete

button.



To edit a shape, click the

Edit

button and edit the shape properties.

Values can only be manually edited he

re,

nothing will be recalculated.

If you wish to have all the values for a shape recalculated, you will need to delete

the shape and then add it again with the new properties.

Aluminum Shape Types

There are ten types of shapes.

Names for each shape type follow the convention of the manufacturer for each shape. If you

know the shape name, you can type the name directly into the

Shape

field on the spreadsheets.

Alternately you may click

the

button to look up a shape and select it.

WF sections

The wide flange shapes

are called out by the designation given them in the aluminum manual.

For example, if you wanted to

use a WF10x11.4 you would

enter WF10X11.4 as the shape name in the database shape field.

Aluminum Association

Standard I

Beams(AA), American Standard(S), Army

Navy(A

N), Canadian(CAN) I

Beams and Wide Flange shapes are

available.

Aluminum

Database

RISA

2D v10

Zee sections (Z)

The Z shapes

are

called out by the designation given them in the ADM manual.

Tee sections (T)

The T shapes

are called out by the designation given them in the ADM manual.

Army

Navy (A

N) shapes are also available.

Solid Rectangular

The Solid Rectangular

sections or bar sections are defined by the user, there are no default shapes. The syntax is "htXbase",

where "ht" is the rectangle height and "base" is the rectangle base (in inches or cm).

For example, 10X4 would be a 10"

deep, 4" width rectangular sha

pe (assuming US Standard units).

These shapes are also be defined in the Shape Editor.

Angles sections (L)

Angles are entered with an "L" prefix.

The syntax is "LlongXshortXthick", where "long" is the long leg length, "short" is the

ort leg length, and "thick" is the thickness, in number of decimals.

For example, L5X3X0.375 is a 5" by 3" angle 0.375"

thick.

Square End Angles (LS) shapes are also available.

Channel sections (CS)

The CS shapes

are called out by the d

esignation given them in the ADM manual. The

Aluminum Association (AA),

American Standard Channels (C) and Car and Ship Building Channels (CS), Canadian Channels (CAN) are available.

Double Sections

The CS shapes

are also available Back

-to-

Back or Front

-to-

Front orientation.

Note



The program currently only performs an analysis of double sections and does not perform a code check of any

kind. This may be added into a future revision of the program.

Round Tube or Pipe (OD) or (NPS)

The Round Tube shapes

are called out by the designation given them in the ADM manual. The

Outer diameter call out is

used as well as the Nominal Pipe Size.

Rect Tube sections (RT)

The RT shapes

are called out by the designation

given them in the ADM manual.

Aluminum

Design

General Reference Manual

Aluminum

Design

Full code checking can be performed on standard aluminum shapes, based on the following codes:



Aluminum Design Manual 2005

Aluminum properties are available in the database and the

values are based on the ADM values (See

Aluminum Database

You may also input your own basic shapes and the properties will be calculated automatically.

Design Parameters

The

Aluminum

tab

on the

MemberSpreadsheet

records the design parameters for the aluminum code checks.

These

parameters may also be assigned graphically.

See

Modifying Member Design Parameters

to learn how to do this.

These parameters are defined for each aluminum member. The entries are explained below.

Label

You may assign a unique

Label

to all of the members. Each label must be unique, so if you try to

enter the same label more

than once you will get an error message.

You may relabel

at any time with the

Relabel

options on the

Tools

menu.

Shape

The member

Shape

or Section Set is reported in the second column.

This value is listed for reference only and

may not be

edited as it is dictated by the entry in the Section/Shape column on the

Primary

tab.

Length

The

member

Length

is reported in the

third

column.

This value may not be edited as it is dependent on the

member end

coordinate

listed on the

Primary D

ata

tab. It is listed here as a reference for unbraced lengths which are discussed in the next

section.

Unbraced Length

You may specify unbraced lengths or have RISA

2D calculate them for you. The unbraced lengths are

Lbout

Lbin

Lcomp

top

and

Lcomp

bot

TheLbvalues,

out and

-inrepresent the unbraced length

for the member

with respect to column type buckling

out of

plane and in plane

, respectively. These

values are used to calculate KL/r ratios for both direction

s, which in turn impact

the calculation of the axial strength, Pn. The KL/r ratios gauge the vulnerability of the member to buckling.

Refer to Section

C4 in Part V of the AISI code for more information on this. Also, Section C4 lists some limiting values f

or KL/r.

These

limiting values are NOT enforced by the program.

The

Lcomp

values,

Lcomp

top

and

Lcomp

bot

, are the unbraced lengths of the compression flanges for

flange buckling due

to flexure

These may be the same as the Lbyy but not necessarily.

Aluminum

Design

RISA

2D v10

For

continuous beams the moment will reverse such that the top and bottom flanges will be in compression for different

portions of the beam span.

Lcomp

top

is the unbraced length of the top flange and

Lcomp

bot

is the unbraced length of the

bottom flange.

left blank these unbraced lengths all default to the member's full length.

The exception to this is if

out

is entered and

Lcomp

top

is left blank,

Lcomp

top

will default to the entered value for

out.

For

physical members

, y

ou can enter the code “

Segment

” in the unbraced length fields and the length of

each

segment will

be used.

A “segment” is the distance between the joints that are on the

physical member

. For example, suppose you have a

physical member

that is 20 feet in le

ngth, and there are two joints along the

physical member

, one 5 feet from the end and

one at 15 feet.

An unbraced length of feet will be used for the

first segment then a value of 10 feet will be used in the middle

segment, and again a value of 5 feet woul

d be used in the last segment

Note



If the intermediate framing members are considered to brace the bottom flange, then you can enter “segment” for

Lcomp

bot. When the “segment” command is used ALL intermediate points along the beam are viewed as brace

poin

ts. Therefore, you may have to delete unused or extraneous points.



The Top Flange is defined as the flange corresponding to the positive local y axis for the member.

For more

information on setting local axes refer to the

Members

section.



The calculated unbraced lengths are listed on the

Member Detail

report.

K Factors (Effective Length Factors)

The

K Factors

are also referred to as effective length factors.

K-out

is for column type buckling

out of plane

and

K-in

is for

buckling

n plane

If a value is entered for a

K Factor

, that value will be used for

the entire length of the physical member

. If an entry is not

made (left blank), the value will internally default to '1' for that

member

RISA

2D is able to approximate the K values

for a member based on the member's sway

condition and end

release

configuration. The K

factor approximation is based on a rational method provided by other codes including AISC,

AISI, etc.

The following table gives the values used for various conditions.

Table Case

End Conditions

Sidesway?

K-Value

(a)

Fixed

.65

(b)

Fixed

Pinned

.80

(c)

Fixed

Yes

1.2

(d)

Pinned

1.0

(e)

Fixed

Free

Yes

2.1

(f)

Pinned

Fixed

Yes

2.0

RISA

2D will recognize a pinned boundary condition for the K

approximation for a full pin, i.e. if all the rotations in the

boundary condition are released.

If any of the rotations in a boundary condition are restrained, the boundary condition is

considered “fixed” for the K approximation.

Any configuration not de

scribed here will be given the default value of 1.0.

If any value that influences these K values is changed, the K approximation should be redone.

For instance, if you have

RISA

2D approximate K values then change some end release designations, you should

redo the K approximations.

Remember that the K

values are

approximations,

and you should check to make sure you agree with all K

values RISA

-2Dassigns.

You can always override a K

value after an approximation by directly entering the value that you want

in the

appropriate field.

Keep in mind that a subsequent approximation will overwrite any manually input values so you will need

to override the approximation each time it is performed.

Limitation:

Aluminum

Design

General Reference Manual

RISA

2D will currently neglect the influence of adjoinin

g framing members when those members are connected at a joint

that also has degrees of freedom restrained by boundary conditions.

For example, suppose a column and beam member

connect at a joint that is restrained for translation in all directions (i.e. t

he joint is "pinned").

The K factor approximation will

neglect the beam member when it calculates the K factor for the column and visa

versa.

The effect will be that the ends of

the members at that joint will be seen as "pinned" and not "fixed" for the K

factor approximation.

Cm-Interactive Bending Coefficient

Cm Coefficients

are described in Section 4.1.1 of the ADM code.

If these entries are left blank, they will be automatically

calculated.

TheCmvalue is influenced by the sway

condition of the memb

er and is dependent on the member's end moments, which

will change from one load combination to the next, so it may be a good idea to leave these entries blank.

Cb-Bending Coefficients

For the aluminum codes,

Cb Coefficients

depends on the moment variati

on over the unbraced length as described in section

ADM 4.9.4. If this entry is left blank, it will be calculated automatically.

Sway Flags

The

Sway Flags

indicate whether the member is to be considered subject to sidesway for bending

in and out of plane

The

Out sway

field is for

out of plane

bending and the

In sway

field is for

in plane bending

Click on the field to check the box

and indicate that the member is subject to sway for that particular direction, or leave the entry blank if the member is brac

edagainst sway.

These sway flags influence the calculation of the K factors as well as the Cm and Cb factors.

Aluminum Design Results

Access the

Code Check

spreadsheet by selecting the

Results

menu and then selecting

Members

Design Results

or by

clicking on the

Design Results

button on the Results toolbar.

The final results of the code checking are the code check values

UC Max

and

Shear UC

These values represents a factored

ratio of actual to allowable load for ASD based on the provisions of ADM

Section 4.

So, if this

value is less than 1.0, the

member passes.

If it is greater than 1.0, the member fails.

If the value is greater than 9.999 it will be listed as "9.999".

The

Shear Check is based on fs/Fs. The

Loc

field tells at what location the maximum code check occu

rs measured from the I

joint

location of the member.

See

Plot Options

–

Members

to learn how to view the code check results graphically.

The remaining columns provide some of the values used in the code check with the equa

tion number itself given in the last

column.

The

Member Detail Report

gives more values used to perform the code check.

The final field lists the controlling equation for the code check.

This will be one of the equations from Sec

tion 4.

For enveloped results the combination that produced the listed code and shear checks is given in the column "lc".

The other

values are the corresponding values and are not necessarily the maximums across all the combinations.

Note

Aluminum

Design

RISA

2D v10



The program curr

ently only performs an analysis of double sections and does not perform a code check of any

kind.



The

Member Detail Report

gives more values used to perform the code check.



See

Spreadsheet Operation

to learn how to use

Find

Sort

and other options.



See

Plot Options

–

Members

to learn how to plot member results.

Aluminum Detail Report

The aluminum detail report has design information fo

r the specific code checks:

The

Max

Bending Check

is based on ADM Section 4, with the governing

Equation

and

Location

listed.

The

Max Shear

Check

is not provided in the AD

specification, this represents fs/Fs with the governing

Location

listed.

The

Max

Defl

Ratio

is based on the entire length of the member.

The

Slender Limit S1

andS2are calculated based on the

Gov Eqn

. The Slenderness Ratio are given based on the Design

Aids in Tables 2

2 thru 2

26 ADM Section VII. The

Slender. Ratio

is also based on the

Gov Eq

and is listed below for all

code checks:

Sec. 3.4.

Slend Ratio

kL/r8kL/r9b/t10(Rb/t)

1/2

Lb/ry12

(Rb/t)

1/2

(d/t)(L

/d)

1/2

(2LbSc)/((IyJ)

1/2)15b/t16b/t17b/t18h/t19h/t20h/t21ae/t

Aluminum

Design

General Reference Manual

Assumptions and Limitations

For all shape types, it is assumed that the axial load on the member is occurring through the member's shear center.

This

means

local secondary moments that may occur if the axial load is not applied through the shear center are not considered.



, effective radius of gyration from Eq 4.9.1

1 is used for doubly symmetric sections beams.



Welded

regions are not checked in RISA

3D.

You can use the welded material properties for the entire member, or

create segments that are welded material in order to check the weld properites.



Connections

are not checked, including web crippling, fatigue or stiffeners.



is assumed to be the small

er ofLb-

out or

-in.

Torsional warping effects are not included.

Torsion stiffness and

stress are calculated as pure torsion only.



in is assumed to be the smaller of

K-outorK-in



Double Sections

The program currently only performs an analysis of

double sections and does not perform a code

check of any kind.

Special Messages

Aluminum Code Check Not Calculated

This message is displayed when the member is not defined with a database shape, is defined as a double section, or an

Aluminum code is not s

pecified on the

Global Parameters

, or no units were specified.

Boundary Conditions

RISA

2D v10

Boundary Conditions

define how the model is externally constrained.

All models must be attached to some external point or

points of support.

You

may define

these

points of support as completely restrained or as partially restrained with a

Spring

You can also define a spring support that has stiffness in only one direction with tension

only or compression

only springs.

Creating and Modifying

There are a number of ways to create or modify

boundary conditions

You may view and edit the data in the

Boundary

Conditions Spreadsheet

, you may dou

ble-click a joint to view and edit its properties,

or you can use the

Modify

Boundaries

tool to graphically assign or modify a possibly large selection of

boundary conditions

Modify Boundary Conditions for Joints

The graphical

Modify Boundary

tool discuss

ed here lets you specify and modify

boundary conditions

graphically. To use

this, you will typically specify the new

boundary condition

, then select the

joints

that you want to assign or modify.

You can modify or assign

joints

one at a time by selecting t

Apply by Clicking/Boxing

option and then click on the

joints

you wish to modify. You may also modify or assign entire selections of

joints

by selecting the

joints

first and then use the

Apply to All Selected

option.

The parameters shown are the same as

those on the

Boundary Conditions Spreadsheet

and are described in

Boundary

Condition Options

. Use the arrow buttons to select the

boundary condition

The

Use?

check boxes next to the data fields indicate whether the particular parameter will be used or not when the

modification is applied. If the box next to a field is checked, that parameter will be applied to any selected

joints

If the box is

NOT checked, the parameter will NOT be applied, even if a value is entered in the field. This lets you easily change one or

two parameters on

joints

without affecting all the rest of the parameters.

To Apply Boundary Conditions

If there is n

ot a model view already open then click

on the

RISA Toolbar

to open a new view and click

turn on the

Drawing Toolbar

if it is not already displayed.

Click the

button and define the

boundary condition

. Check the

Use?

Box for the items

to apply.

You may apply the

boundary condition

by choosing

joints

on the fly or apply it to a selection of

joints

To choose

joints

on the fly, choose

Apply Entries by Clicking/Boxing Joints

and click

Apply

. Click/Box the joints

with the left mouse button

Boundary Conditions

General Reference Manual

To apply the

boundary condition

to a selection of

joints

, choose

Apply Entries to All Selected Joints

and click

Apply

Note



To apply more

boundaries

with different conditions, press CTRL

D to recall the

Boundary Conditions Dialog

.You may also view and e

dit boundary conditions by double

clicking on a joint.



You may also specify or edit

boundary conditions

in the

Boundary Conditions Spreadsheet



To assign a Footing, you must have RISAFoot installed on the computer and you must first create a footing group

in the

Footing

spreadsheet.



You may undo any mistakes by clicking the

Undo

button.

Boundary Conditions

Spreadsheet

The

Boundary Conditions Spr

eadsheet

records the

boundaries

for the

joints

and may be accessed by selecting

Boundary

Conditions

on the

Spreadsheets Menu

The

Joint Label

column contains

the label of the

joint

that is restrained.

The last column may contain the label for the spread

footing that is assigned to the joint. The

Footing

column is only available if a current version of RISAFoot is also loaded on

the computer.

The remaining colu

mns record the boundary conditions that apply to the joint. There are

three

degrees of freedom

for each

joint (

translation,

rotation), so there are

three

columns for degrees of freedom. The last column records the foo

ting group,

if any, applied to the joint. Footings may only be used if RISAFoot is also loaded on the computer. The boundary conditions

are entered in these remaining columns by selecting the cell, clicking

and choosing from the boundary options. You may

also type them in directly.

Boundary Condition

Options

Free

joints

have no restraint in any of the degrees of freedom and need

not be listed on the

Boundary Conditions

Spreadsheet

. The following are the valid

boundary condition

options that may be used

for the three degrees of freedom

Note



Models that contain compression

only or tension

only springs must be iterated

until the sol

ution converges.

Convergence is achieved when no more load reversals are detected in the springs. During the iteration process,

each spring

is checked, and if any springs are turned off (or back on), the stiffness matrix

is rebuilt and model is

resolved.

This can take quite a bit longer than a regular static solution.



You can enter the first letter of the option ("R" for Reaction, "S" for Spring, etc.) rather than typing out the entire

code. RISA

-2Dfills in the rest automatically.

The exceptions are the S

LAVE and STORY entries, where the full

word does have to be entered (since "S" denotes a spring).

Boundary Conditions

RISA

2D v10

Boundary Condition at ALL Joints

The entry "AL

may be entered in the

Joint Label

field. The boundary conditions entered on this line will be applied to

ALL the joints not otherwise listed. This is useful if you should want to lock certain directions of movement for all or most

the joints.

Note



a joint is explicitly listed with boundary conditions, those boundary conditions override the "ALL" conditions

for all

directions.

The "ALL" specified boundary codes apply only to those joints NOT otherwise listed on the

Boundary Conditions Spreadsheet

Reaction

Boundary Condition

The "R" code, for

Reaction

, specifies full restraint for the

indicated

direction. No movement will be allowed in the

indicated

directio

n for this

joint

. Furthermore, the reaction will be calculated at this

joint, for this direction

Fixed Boundary Condition

The "F" code, for

Fixed

, specifies full restraint for the joint in the indicated direction. The difference between "Fixed" and

"Reaction" is that for the "Fixed" code, no reaction is calculated. The "Fixed" condition actually

removes the degree of

freedom from the solution, which is why the reaction value is not available. If you aren't interested in the reaction value,

using the "Fixed" code will result in a slightly smaller model and less output.

Spring

Boundary Condition

The "Snnn" code, for

Spring

, models a spring attached to the

joint

in the

indicated

direction. The "nnn" portion of the code is

the numerical magnitude of the springs' st

iffness.

The units for the spring stiffness depend upon whether the spring is

translational or rotational.

The appropriate units are shown at the top of the column.

For example, if a spring of stiffness 1000 Kips per Inch were desired in the

direction a

t a particular

joint

, for that

joint

you

would enter 'S1000' for the

X direction boundary condition

Compression

Only Springs

The

"CSnnn" code, for

Compression

Only Springs

, models a one way "compression

only" spring

attached to the

joint

in the

indicated

direction. This spring has stiffness for negative displacements and NO stiffness for positive displacements

The

"nnn" portion of

the code is the numerical magnitude of the springs' stiffness. The spring stiffness units are the same as those

for a normal spring.

Compression

only springs are useful as soil

springs when analyzing foundations that may have uplift.

For example, if a comp

ression

only (CS) spring with a stiffness of 500k/in were desired in the

direction at a certain

joint,you would enter 'CS500' for the

Y direction boundary condition

This means that all displacements at this

joint

in the

negative Y

direction will be res

isted with a stiffness of 500k/in. However

the

joint

is free to move in the

positive Y

direction.



When a model contains T/C only springs, the program must iterate the solution until it converges. Convergence is

achieved when no more load reversals are dete

cted in the T/C only springs. During the iteration

process, each T/C

only

boundary condition

is checked. If any springs are turned off (or turned back on), the stiffness matrix

rebuilt and model is resolved.

For models with lots of T/C only elements, th

is can take a bit longer than a regular

static solution.

Tension

Only Springs

The "TSnnn" code, for

Tension

Only Springs

, models a one way "tension

only" spring

attached to the

joint

in the

indicated

direction. This spring has

stiffness for positive displacements and NO stiffness for negative displacements. The "nnn" portion

of the code is the numerical magnitude of the springs' stiffness. The spring stiffness units are the same as for a normal spr

ing.

Boundary Conditions

General Reference Manual

For example, if a tension

only (TS) spring with a stiffness of 500k/in. were desired in the

direction at a certain

joint

, you

would enter 'TS500' for the

Y direction boundary condition

This means that all displacements at this

joint

in the

positive Y

direction will be resisted w

ith a stiffness of 500k/in. However

the

joint

is free to move in the

negative Y

direction.



When a model contains T/C only springs, the program must iterate the solution until it converges. Convergence is

achieved when no more load reversals are detected in

the T/C only springs. During the iteration

process, each T/C

only

boundary condition

is checked. If any springs are turned off (or turned back on), the stiffness matrix

rebuilt and model is resolved.

For models with lots of T/C only elements, this can

take a bit longer than a regular

static solution.

Slaved Joints

You may slave any or all of the joint degrees of freedom to another joint.

See

Slaving Joints

r more information.

Story Drift Joints



The

Boundary

spreadsheet is also used to record joints to be used for story drift

calculation.

For example, to

indicate that a particular joint is to represent the fourth story lev

el for X direction drift, you would enter “STORY

4” for the X direction boundary condition for the joint.

These STORY entries may only be made in the

translation degrees of freedom.

See

Drift

for more information.

Footings

at Boundary Conditions

If the current version of RISAFoot has been installed on your computer, then you can automatically integrate the Footing

design directly into your RISA

-2Dresults. For more information on this procedure, refer to the

Footings Design

section.

Boundary Conditions at Wall Panels

If the edge of a wall panel is to be viewed as continuously pinned or fixed, then the boundary condition for that wall must b

set in the

wall panel edi

tor

. Situations can arise where there is a difference between the wall panel edge boundarycondition

and the boundary condition defined at a joint along that edge. In these situations the joint boundary condition will always

govern for that joint. However,

the rest of the edge will be based on the wall panel's boundary conditions.

Cold Formed Steel

Databases

RISA

2D v10

Cold Formed Steel

Databases

Shapes are organized in the database by manufacturer.

Common shapes are supported

such as C sections with and without

lips, Z sections with and without lips, and Hat sections without lips.

Each of these shape types may be used as single section,

a back to back section, or a face to face section. You may type in the names directly, selec

t shapes from these databases or

add your own shapes.

RISA currently supports the following common Cold Formed steel databases: AISI 1999 and 2001, Dale

Incor, Dietrich,

Marino

Ware, and SSMA.

You must select "AISI Custom" as the Manufacturer to enter cu

stom shapes.

To Select a Cold Formed Database Shape

From the

Cold Formed

Section Sets

tab on the

Spreadsheet

, or the

Primary

tab of the

Members Sprea

dsheet

move

the cursor to the

Shape

field and click

.2.Specify the database and shape type you wish to use and then select from the list of available shapes by cli

cking on

Custom vs. Manufacturer Shapes

You can enter your own cold formed shapes as well as use those provided in the

manufacturer database.

When the cold

formed database type is selected, you'll notice a "Manufacturer" list box that appears in the Shape Selection dialog.

You can

specify a manufacturer or choose “Custom” to select, add or edit your own custom shapes.

ew shape properties are

calculated using the linear method described in Part I of the AISI code.

Database Files

The cold formed manufacturer shape databases are stored in the file aisidb32.fil, and the custom cold formed shapes are

stored in the file ais

icust.fil.

Cold Formed Steel

Databases

General Reference Manual

To Add a Database Shape

On the

RISA Toolbar

click the

Edit Shape Database

button.

Select the cold formed tab and set the Manufacturer type to "Custom", then select the shape type you wish to add and

click the

Add

button.

Specify a name for the shape and fill in the

Basic Propertie

Click

Calc Props

to determine the shape properties.

Note



Alterations to the shape database are not permanent unless you agree to save them.

Changes that are not saved

only remain valid for the current session and will not be present the next time you s

tart RISA.



New shapes are added to the bottom of the database.



To delete a shape, specify the database and shape type you wish to delete and then click the

Delete

button.



To edit a shape, click the

Edit

button and edit the shape properties.

Values can o

nly be manually edited here,

nothing will be recalculated.

If you wish to have all the values for a shape recalculated, you will need to delete

the shape and then add it again with the new properties.

Manufacturer shapes cannot be edited, only custom

sha

pes can be edited.

Cold Formed Shape Types

There are five types of shapes.

Names for each shape type follow the convention of the manufacturer for each shape. If you

know the shape name, you can type the name directly into the

Shape

field on the spreadsheets.

Alternately you may click

the

button to look up a shape and select it.

C sections without lips (CU)

For the AI

SI database, CU shapes

are called out by the designation given them in the AISI steel manual.

For example, if you

wanted a 12" deep unstiffened C section, you'd call it out as 12CU1.25x071.

The '12' is the depth, the CU specifies a C

section without lips

, the '1.25' is the flange width, and the '071' is the decimal thickness.

Other manufacturer databases

generally follow similar conventions.

Cold Formed Steel

Databases

RISA

2D v10

C sections with lips (CS)

For the AISI database, CS shapes

are called out by the designation giv

en them in the AISI steel manual.

Other manufacturer

databases generally follow similar conventions.

Z sections without lips (ZU)

For the AISI database, ZU shapes

are called out by the designation given them in the AISI steel manual.

her manufacturer

databases generally follow similar conventions.

Z sections with lips (ZS)

For the AISI database, ZS shapes

are called out by the designation given them in the AISI steel manual.

Other manufacturer

databases generally fol

low similar conventions.

Hat sections without lips (HU)

For the AISI database, HU shapes

are called out by the designation given them in the AISI steel manual.

Other manufacturer

databases generally follow similar conventions.

Double Sec

tions

For each of the five shape types the selected shape may be used as a standard single section or as a double section. The

choices for double sections are 'Back to Back' and 'Face to Face'. A typical double section is designated with a "2

" preceding

he shape name and a "

BB" (Back to Back) or "

FF" (Face to Face) following the shape name. For example, a "2

12CU1.25x071

FF" section represents two 12" deep C sections with 1.25" wide flanges and a 0.071" thickness placed face to

face.

Note



The program cu

rrently only performs an analysis of double sections and does not perform a code check of any

kind. This may be added into a future revision of the program.

Cold Formed Steel

Design

General Reference Manual

Cold Formed Steel

Design

Full code checking can be performed on

standard cold formed steel shapes, based on the following codes:



The 1996 edition of the AISI code with 1999 Supplement (AISI

99 ASD and LRFD)



The 2001 edition of the AISI code (AISI

2001 ASD and LRFD)



The 2001 editio

n of the Mexican code (CANACERO

2001 ASD and LRFD)



The 2001 edition of the Canadian code (CSA S136

01 LSD)

Cold formed shape properties are available in the database and the values are based on the AISI or manufacturer values,

whichever is selected (See

Cold Formed Steel Database

You may also input your own basic shapes and the properties will

be calculated automatically.

Design Parameters

The

Cold Formed

tab on the

Members

Spreadshee

record

the design parameters for the cold formed steel code checks.

These parameters may also be assigned graphically.

See

Modifying Member Design Parameters

to learn how to do this.

These parameters are defined for each cold formed member. The entries are explained below.

Label

You may assign a unique

Label

to all of the members. Each label must be unique, so if you

try to enter the same label more

than once you will get an error message.

You may relabel

at any time with the

Relabel

options on the

Tools

menu.

Shape

The member

Shape

or Section Set is reported in the second column.

This value is listed for reference on

ly and may not be

edited as it is dictated by the entry in the Section/Shape column on the

Primary

tab.

Length

The

member

Length

is reported in the

third

column.

This value may not be edited as it is dependent on the

member end

coordinates

listed on the

rimary Data

tab. It is listed here as a reference for unbraced lengths which are discussed in the

next section.

Unbraced Length

You ma

y specify unbraced lengths or have RISA

-2Dcalculate them for you.

The unbraced lengths are

Lbout

Lbin

Lcomp

top

and

Lcomp

bot

TheLbvalues,

out and

in,

represent the unbraced length

for the member

with respect to column type buckling

out of

pla

ne and in plane

, respectively. These

values are used to calculate KL/r ratios for both directions, which in turn impact

the calculation of the axial strength, Pn. The KL/r ratios gauge the vulnerability of the member to buckling.

Refer to Section

Cold Formed Steel

Design

RISA

2D v10

C4 in

Part V of the AISI code for more information on this. Also, Section C4 lists some limiting values for KL/r.

These

limiting values are NOT enforced by the program.

The

Lcomp

values,

Lcomp

top

and

Lcomp

bot

, are the unbraced lengths of the compression flang

es for

flange buckling due

to flexure

These may be the same as the

out value, but not necessarily.

The

Lcomp

values are used in the calculation of

bending strength, Mn. Refer to Section C3 in Part V of the AISI code for more information on this. In par

ticular, Lcomp is

used in equation C3.1.2.1.

8 as shown in Supplement 1 to the 1999 or the 2001 codes.

For continuous beams the moment will reverse such that the top and bottom flanges will be in compression for different

portions of the beam span.

Lcomp

-top

is the unbraced length of the top flange and

Lcomp

bot

is the unbraced length of the

bottom flange.

If left blank these unbraced lengths all default to the membe

r's full length.

The exception to this is if

out is entered and

Lcomp

top

is left blank,

Lcomp

top

will default to the entered value for

out.

For

physical members

, you can enter the code “

Segment

” in the unbraced length fie

lds and the length of

each

segment will

be used.

A “segment” is the distance between the joints that are on the

physical member

. For example, suppose you have a

physical member

that is 20 feet in length, and there are two joints along the

physical member

one 5 feet from the end and

one at 15 feet.

An unbraced length of

feet will be used for the

first segment, then a value of 10 feet will be used in the

middle segment, and again a value of 5 feet would be used in the last segment

Note



If the intermediate

framing members are considered to brace the bottom flange, then you can enter “segment” for

Lcomp

bot. When the “segment” command is used ALL intermediate points along the beam are viewed as brace

points. Therefore, you may have to delete unused or extran

eous points.



The Top Flange is defined as the flange corresponding to the positive local y axis for the member.

For more

information on setting local axes refer to the

Members

section.



The calculated unbraced lengths are listed o

n the

Member Detail

report.

K Factors (Effective Length Factors)

The

K Factors

are also referred to as effective length factors.

K-out

is for column type buckling

out of plane

and

K-in

is for

buckling

in plane

.Ifa value is entered for a

K Factor

, that value will be used for

the entire length of the physical member

. If an entry is not

made (left blank), the value will internally default to '1' for that

member

See the AISI code commentary for Section C4 for

an exp

lanation of how to calculate K Factors.

RISA

-2Dis able to approximate the K values for a member based on the member's sway

condition and end

release

configuration. The K

factor approximation is based on Table C

C4.1, found on page VI

71 of the AISI code.

The

following table gives the values used for various conditions.

Table Case

End Conditions

Sidesway?

K-Value

(a)

Fixed

.65

(b)

Fixed

Pinned

.80

(c)

Fixed

Yes

1.2

Cold Formed Steel

Design

General Reference Manual

(d)

Pinned

1.0

(e)

Fixed

Free

Yes

2.1

(f)

Pinned

Fixed

Yes

2.0

RISA

-2Dwill recognize a pinned boundary condition for the K approximation for a full pin, i.e. if all the rotations in the

boundary condition are released.

If any of the rotations in a boundary condition are restrained, the boundary condition is

nsidered “fixed” for the K approximation.

Any configuration not described here will be given the default value of 1.0.

If any value that influences these K values is changed, the K approximation should be redone.

For instance, if you have

RISA

-2Dapproxim

ate K values then change some end release designations, you should redo the K approximations.

Remember that the K

values are

approximations,

and you should check to make sure you agree with all K

values RISA

-2Dassigns.

You can always override a K

value a

fter an approximation by directly entering the value that you want in the

appropriate field.

Keep in mind that a subsequent approximation will overwrite any manually input values so you will need

to override the approximation each time it is performed.

mitation:

RISA

-2Dwill currently neglect the influence of adjoining framing members when those members are connected at a joint

that also has degrees of freedom restrained by boundary conditions.

For example, suppose a column and beam member

connect at a

joint that is restrained for translation in

both

directions (i.e. the joint is "pinned").

The K factor approximation

will neglect the beam member when it calculates the K factor for the column and visa

versa.

The effect will be that the ends

of the membe

rs at that joint will be seen as "pinned" and not "fixed" for the K factor approximation.

Sway Flags

The

Sway Flags

indicate whether the member is to be considered subject to sidesway for bend

ing

in and out of plane

The

Out sway

field is for

out of plane

bending and the

In sway

field is for

in plane bending

Click on the field to check the box

and indicate that the member is subject to sway for that particular direction, or leave the entry bla

nk if the member is braced

against sway.

These sway flags influence the calculation of the K factors as well as the Cm and Cb factors.

Cm-Interactive Bending Coefficient

Cm Coefficients

are described in Section C5 of the AISI code.

If these entries are left blank, they will be automatically

calculated.

TheCmvalue is influenced by the sway

condition of the member and is dependent on the member's end moments, which

ll change from one load combination to the next, so it may be a good idea to leave these entries blank.

Cb-Bending Coefficients

For the cold formed codes,

Cb Coefficients

are used in the calculation o

f the nominal flexural strength, Mn. If this entry is

left blank, it will be calculated automatically.

R Value

The

R Value

for cold formed steel design is described in section C3.1.3 of the AISI code and is used to

calculate the moment

capacity of beams that have one flange fastened to deck or sheathing. This value only applies to C or Z members and can

vary from 0.4 to 0.7 based on the depth of the member (See table C3.1.3

1 in the AISI Supplement for the actual val

ues).

If a value is entered by the user, that value will be used by the program in the moment capacity calculation of the member.

There are a number of restrictions that must be met to use this section of the code for moment capacity and the user is

respon

sible to check that these restrictions are satisfied.

Note

Cold Formed Steel

Design

RISA

2D v10



If the R value is entered, the program will use section C3.1.3 when performing moment capacity calculations and

will ignore the standard LTB checks from section 3.1.2.

Phi Factors

The following tab

le provides a list of safety factors (ASD) and resistance factors (LRFD and LSD) being used for different

codes.

Code

FtFcFbFvWtWcWbW

AISI ASD 99

1.67

1.8

1.67

1.5/1.67

AISI LRFD 99

0.95

0.85

0.95/0.9

1.0/0.9

AISI ASD 01

1.67

1.8

1.67

1.6

AISI LRFD 01

0.9

0.85

0.95/0.9

0.95

Canacero ASD 01

1.67

1.8

1.67

1.6

Canacero LRFD 01

0.9

0.85

0.95/0.9

0.95

CSA S136

-010.9

0.8

0.9

0.8

AISI Steel Code Check Results

Access the

Code Check

spreadsheet by selecting the

Results

menu and then selecting

Members

Design Results

or by

clicking on the

Design Res

ults

button on the Results toolbar.

The final results of the code checking are the code check values

UC Max

and

Shear UC

These values represents a

factored

ratio of actual to allowable load for ASD or ultimate load to design strength for LRFD or LSD, based on the provisions of

Section C5.

Section 3.3.1 and 3.3.2 are also used to check combined bending and shear.

So, if this value is less than 1.0,

the

member passes.

If it is greater than 1.0, the member fails.

If the value is greater than 9.999 it will be listed as "9.999".

The

Shear Check is based on section C3.2.1. The

Loc

field tells at what location the maximum code check occurs measured fro

the I-joint location of the member.

See

Plot Options

–

Members

to learn how to view the code check results graphically.

The remaining columns, discussed below, provide some of the values used in the code check with the e

quation number itself

given in the last column.

The

Member Detail Report

gives more values used to perform the code check.

For ASD code checking, Pn, Tn, and Mn are the member capacities calculated for the member.

Pn is calculate

d according to

the provisions of AISI 1999 / 2001, Section C4.

Tn is based on Section C2.

The Mn values are calculated based on Section

C3.

For LRFD or LSD, the factored compression Phi*Pn, factored tension, Phi*Tn, and factored moment strengths Phi*Mn

alues are displayed.

For tension Tn, the value is fy * area, per Section C2.

Compression Pn is calculated per Section C4.

The Mn values are calculated per Section C3.

Cb is set to 1.0 if not specifically entered by the user, which is conservative.

The

Cm coefficients, described in Section C5

are also listed.

These also are influenced by the sway flag settings.

The final field lists the controlling equation for the code check.

This will be one of the equations from Section C5 or Section

C3.3.

For envel

oped results the combination that produced the listed code and shear checks is given in the column "lc".

The other

values are the corresponding values and are not necessarily the maximums across all the combinations.

Cold Formed Steel

Design

General Reference Manual

Note



The program currently only perfor

ms an analysis of double sections and does not perform a code check of any

kind.



The

Member Detail Report

gives more values used to perform the code check.



See

Spreadsheet Operations

to learn how t

o use

Find

Sort

and other options.



See

Plot Options

–

Members

to learn how to plot member results.

Assumptions and Limitations

For all shape types, it is assumed that the axial

load on the member is occurring through the member's shear center.

This

means local secondary moments that may occur if the axial load is not applied through the shear center are not considered.

Iterations for the effective section modulus (Se and Sc) are

ended when a difference less than 1% is achieved in the neutral

axis distance calculation with a maximum of 5 iterations.

Holes in sections are not considered in the shear strength

calculations or for effective width calculations.

Deflections are based o

n the full section properties, not the effective section

properties.

is assumed to be the smaller of

out

Lcomp

Torsional warping effects are not included.

Torsion stiffness and stress

are calculated as pure torsion only.

Web crippling is not consi

dered.

in section C3.1.2.1 is assumed to be 1.0.

All conditions listed for the use of C3.1.3

1 are assumed satisfied.

Section C3.1.4

is not considered in the calculation of Mn.

Effects of shear stiffeners for section C3.2.1 are not considered.

Only stro

ng axis

bending and strong axis shear are considered for equation C3.3.1 (combined bending and shear).

Section C4.4 is not considered in the calculation of the axial strength at this time.

Z Shapes

–

The bracing length in

Lbout is assumed to brace the mino

r principal axis.

Z sections in compression are assumed

to buckle in Euler buckling about their weakest principal axis. The value of r

min

is used rather than the geometric r

and r

values.

H Shapes

–

Hat sections in bending about the y

y axis such that th

e brims are in compression are assumed braced such that

the brims cannot each fail in lateral torsional buckling independently.

Double Sections

The program currently only performs an analysis of double sections and does not perform a code check of

any ki

nd.

Slenderness Limitations

The w/t limits of Section B1.1 are enforced. However, the shear lag effects (section B1.1c) are

not enforced.

Special Messages

AISI Code Check Not Calculated

This message is displayed when the member is not defined with a dat

abase shape, or is defined as a double section, or a steel

code is not specified on the

Global Parameters

, or no units were specified.

Can't do code check, stiffener D/w > 0.8 (Sect. B4.2)

The ratio D/w exceeds the limiting criteria listed in Section B4.2

for simple lip stiffeners.

(“D” and “w” are length of the

stiffener and the flat length of the flange as defined in B4.2)

Stiffener angle gamma is < 40 or > 140 (Sect. B4.2)

The angle (gamma) for a simple lip stiffener must be greater or equal to 40 degre

es or less than or equal to 140 degrees per

the criteria in section B4.2.

The angle gamma for this shape is outside this range.

Cold Formed Steel

Design

RISA

2D v10

Can't do code check, flange w/t > limit (Sect. B1.1)

The ratio w/t exceeds the limiting criteria listed in section B1.1 for fla

nges.

A value of 60 is used per the 1999 supplement or

2001 code for unstiffened elements and elements stiffened with simple lips.

Can't do code check, web h/t > 200 (Sect. B1.2)

The ratio h/t exceeds the limiting criteria listed in section B1.2 for webs.

The program currently considers all webs as

unreinforced, so a value of 200 is used as the limit.

Concrete

Database

General Reference Manual

Concrete

Database

There

are two types of shapes

currently supported, Rectangular

and Circular

If you’re familiar with the shape definitions,

you can type the name directly into the appropriate field. Alternately you may click the

button to have the progra

generate the desired shape definition for you.

Rectangular Sections

Rectangular

sections are defined using a parametric shape code si

nce a rectangular shape may be any depth or width. The

code is CRECT'depth'X'width', where 'depth' and 'width' are the values in the current dimension units. For example, if you

wanted a beam that was 18" deep and 12" wide, you would enter "CRECT18X12". No

te that the dimensions can also be

decimal values like "18.25".

Circular Sections

Circular/Round

sections are also defined using a parametric shape code since a round shape may have any diameter. The

code is CRND'diameter', where 'diameter' is the value in

the current dimension units. For example, if you wanted a column

that was 14" in diameter, you would enter "CRND14".

Note that the dimension can also be a decimal value like "14.5".

Rebar Layout Database

Pressing the

button on the

RISA Toolbar

will open the database that is used for creating and storing custom rebar

layouts. This allows the user to create multi

ple layers of bars and add in compression reinforcement or unusual bar

arrangements.

These reinforcement layouts may be assigned to beam

or column

members in the same way as the other concrete design

parameters are assigned.

This can be done on the

Concre

tabs of the

Members Spreadsheet

from the

Design

tab of the

Member Information Dialog

or from the

Modify Members Dialog

Beam

Rebar Layouts

Since beams are only designed for uniaxial bending, the only requirements for the beam layouts are that you spec

ify the

depth at which the bars are located and the size & number of the bars that are present at that depth.

You can specify the depth

with respect to the top surface of the beam or the bottom surface.

Concrete

Database

RISA

2D v10

The

Start

and

End

locations dictate the location along the length of the beam where these bars will be present.

You can use

these entries to specify partial length bars that will only be present in locations with a

higher moment demand. If the bar

should be present for the entire length of the beam, the start location should be '0' and the end location should be '%100' a

shown in the dialog above.

Note



While the rebar layout sheet resembles one of RISA's spreadshe

ets in appearance it is NOT a spreadsheet and

standard TAB controls will not work. Instead, the arrow keys or the new arrow buttons

can be used to

advance from cell to cell.

Rectan

gular Column Rebar Layouts

Since columns are designed for biaxial bending, they require more information about the location and arrangement of the

bars.

Normally, column bars are arranged in

layers

One 'top' and one 'bottom' horizontal layer must

always

be defined, each

containing at least two bars.

These layers, as well as any additional horizontal layers, will be specified by entering a

value

to specify the depth from the top or bottom fiber to the centerline of the reinforcing steel.

The number an

d size of the bars

must then be entered.

Thez1andz2values dictate where the first and last bar in that layer are located.

Additional bars in

that layer will be placed so that they are evenly spaced in that layer.

Concrete

Database

General Reference Manual

Vertical layers can be specified by entering a

value specifying the depth from the right or left most fiber to the centerline

of the reinforcing steel.

The number and size of

the bars must then be entered.

Thez1andz2values are ignored for vertical

layers because the bars will be assumed to be evenly spaced between the required top and bottom layers referred to

previously.

If this is not desired, then the side bars shoul

d be entered individually as

custom single bars

Custom single bars are specified by their y and z coordinates measured from the local y and z

axis respectively.

A positive y

coordinate would place the bar closer to the top fiber and a negative y coordina

te would place the bar closer to the bottom

fiber.

Similarly, a positive z coordinate would place the bar closer to the right side and a negative z coordinate would place

the bar closer to the left side.

The

Start

and

End

locations dictate the location al

ong the length of the member where these bars will be present.

You can

use these entries to specify partial length bars that will only be present in locations with a higher moment demand. If the b

should be present for the entire length of the member, t

he start location should be '0' and the end location should be '

%100'

shown in the dialog above.

Circular Column Rebar Layouts

For circular columns, you may specify equally spaced concentric

rings

of bars at given depths,

, measured from the

exterior

fiber of the column

You may also specify custom single bars.

Custom single bars are specified by their y and z coordinates measured from the local y and z axis respectively.

A positive y

coordinate would place the bar closer to the top fiber and a negat

ive y coordinate would place the bar closer to the bottom

fiber.

Similarly, a positive z coordinate would place the bar closer to the right side and a negative z coordinate would place

the bar closer to the left side.

Concrete

Database

RISA

2D v10

The

Start

and

End

locations dictate the location along the length of the member where these bars will be present.

You can

use these entries to specify partial length bars that will

only be present in locations with a higher moment demand. If the bar

should be present for the entire length of the member, the start location should be '0' and the end location should be '

%100'

shown in the dialog above.

Note



While the rebar layout

sheet resembles one of RISA's spreadsheets in appearance it is NOT a spreadsheet and

standard TAB controls will not work. Instead, the arrow keys or the new arrow buttons

can be use

d to

advance from cell to cell.

Shear Rebar Layouts

These rebar layouts

may be assigned to either columns or beams.

They

are specified by giving the size and spacing of the

bars as well as the location on the

member

where that reinforcement will be presen

Concrete

Database

General Reference Manual

The

Start

and

End

locations dictate the location along the length of the

member

where these bars will be present.

You can

use these entries to specify pa

rtial length reinforcement that will only be present in locations with a higher shear demand. If

the reinforcement should be present for the entire length of the

member

, the start location should be '0' and the end location

should be '%100' as shown in the

dialog above.

Note



While the rebar layout sheet resembles one of RISA's spreadsheets in appearance it is NOT a spreadsheet and

standard TAB controls will not work. Instead, the arrow keys or the new arrow buttons

can be used to

advance from cell to cell.

Concrete

Design

RISA

2D v10

Concrete

Design

Concrete

design and optimization can be performed for

standard

concrete shapes based on the following codes:



The 1999, 2002, and 2005 Editions of ACI 318



The 1997 Edition of the British code (BS 8110)



The 1992 EuroCode (EC2) and the British publication of the 2004 Eurocode (BSEN)



The

1994 Edition of the Canadian code

(CSA

A23.3).



The 2000 Edition of t

he Indian code (IS 456)



The 2001 Edition of the Australian code (AS 3600)



The 1995 Edition of the New Zealand code (NZS 3101)



The 2004 Edition of the Mexican code (NTC

DF)The 2007 Edition of the Saudi Building Code (SBC 304)

The program will design the lo

ngitudinal and shear reinforcement for rectangular beams

and rectangular or circular column

These calculations encompass all the code requirements except those noted in the

Limitations

section of this document.

The

program also

provides reinforcement detailing information for concrete beams

and interaction diagrams for concrete columns

in the

member

detail reports.

To Apply a Concrete Design Code

On the

Code

tab of

Global Parameters Dialog

, select the concrete code from the drop

down list.

Click

Apply

orOK.

Concrete Spans

RISA

-2Dwill automatically break a concrete physical member into spans based on the number of internal supports. Each

internal

joint

is NOT automatically treated as a s

upport. Instead, we go through the whole model geometry to determine

where a beam

or column

is supported. Note that for a physical member to see a support, there must be a

joint

at that support

point.

If a physical column and a physical beam cross each oth

er without a joint at their intersection, then no support / span

will be detected and they will not be connected.

Beam member

type

s are supported by the following:

Vertical Boundary Conditions (Fixed, Reaction), Column Members,

Near Vertical Plate Elements

and other Beam Members that are supporting that member.

Column member

type

s are supported by the following:

Horizontal Boundary Conditions (Fixed, Reaction, Spring),

Beam

Members

, Near Horizontal Plate Elements,

and Rigid Diaphragms.

Note



The quickest

way to create new joints at beam / column intersections is to run a Model Merge.



The program's ability to recognize spans is important because it will give you more relevant span to span

information without overwhelming you with independent design results

for each finite element segment that

comprises your physical member.



For continuous beam members, the program will evaluate the framing to determine which beams elements are

supporting other beam elements so that only supporting members are treated as supp

orts and not visa versa.



Currently, members of type HBrace, VBrace, and None do not affect the span distances.

Nor do any arbitrary

joints within each span along a member.

Concrete

Design

General Reference Manual

Concrete Design Parameters

Columns

e Concrete

Column

tab on the

Members Spreadsheet

records the design parameters for the code checks of concrete

columns. These parameters may also be assigned graphically. See

Modifying Member Design Parameters

to learn how to d

this.

The following parameters can be defined for each concrete column.

Label

You may assign a unique

Label

to all of the members. Each label must be unique,

so if you try to enter the same label more

than once you will get an error message. You may relabel

at any time with the

Relabel

options on the

Tools

menu.

Shape

The member

Shape

or Section Set is reported in the second column.

This value is listed for re

ference only and may not be

edited as it is dictated by the entry in the Section/Shape column on the

Primary

tab.

Length

The member

Length

is reported in the third column.

This value may not be edited as it is dependent on the member end

coordinates liste

d on the

Primary Data

tab. It is listed here as a reference for unbraced lengths which are discussed in the

next section.

Unbraced Length

You may

specify unbraced lengths or have RISA

-2Dcalculate them for you. The unbraced lengths are

Lu-out

and

Lu-in

TheLuvalues,

Lu-out

and

Lu-in

, represent the unbraced length of column members with respect to column type buckling

out of plane and in plane

, res

pectively. These

values are used to calculate KL/r ratios for both directions, which in turn

impact the calculation of axial strength, Pn. The KL/r ratios gauge the vulnerability of the member to buckling. Refer to

Sections 10.12 and 10.13 of the ACI co

de for more information on this. Also, Section 10.11.5 lists the limiting values for

KL/r.

If left blank these unbraced lengths all default to the member's full length.

For

physical members

, you can enter the code “

Segment

” in the

unbraced length fields and the length of each segment will

be used.

A “segment” is the distance between the joints that are on the physical member. For example, suppose you have a

physical member

that is 20 feet in length, and there are two joints along t

he physical member, one 5 feet from the end and

one at 15 feet.

An unbraced length of 5 feet will be used for the first segment, then a value of 10 feet will be used in the

middle segment, and again a value of 5 feet would be used in the last segment.

Note



When the "segment" code is used, ALL joints on a column will be considered to brace the column for that type of

buckling, even if a joint is associated with a member that would actually only brace the column against buckling in

the other local axis.

Ther

efore, the "segment" code should only be used for columns that are truly braced in that

direction at each interior joint.



The calculated unbraced lengths are listed on the

Member Detail

report.

Concrete

Design

RISA

2D v10

K Factors (Effective Length Factors)

The

K Factors

are also referred to as effective length factors.

K-out

is for column type buckling

out of plane

and

K-in

is for

buckling

in plane

If a value is entered for a

K Factor

, that value will be used for

the entire length of the physical

member

. If an entry is not

made (left blank), the value will internally default to '1' for that

member

See Section R10.12.1 of the ACI commentary for an

explanation of how to calculate K Factors.

RISA

2D is able to approximate the K

values for a column ba

sed on the member's sway

condition and end

release

configuration. The K

factor approximation is based on the idealized tables given in the AISC steel specification. The

following table gives the values used for various conditions.

Table Case

End Conditions

Sidesway?

K-Value

(a)

Fixed

.65

(b)

Fixed

Pinned

.80

(c)

Fixed

Yes

1.2

(d)

Pinned

1.0

(e)

Fixed

Free

Yes

2.1

(f)

Pinned

Fixed

Yes

2.0

Note



This is an approximation of K

values and is NOT based on the Jackson and Moreland

Alignment Charts

presented in Section R10.12.1 of the ACI commentary.

RISA

2D will recognize a pinned boundary condition for the K approximation for a full pin, i.e. if all the rotations in the

boundary condition are released.

If any of the rotations in

a boundary condition are restrained, the boundary condition is

considered “fixed” for the K approximation.

Any configuration not described here will be given the default value of 1.0.

If any value that influences these K values is changed, the K approximat

ion should be redone.

For instance, if you have

RISA

2D approximate K

values then change some end release designations, you should redo the K approximations.

Remember that the K

values are

approximations,

and you should check to make sure you agree with a

ll K-values RISA

-2Dassigns.

You can always override a K

value after an approximation by directly entering the value that you want in the

appropriate field.

Keep in mind that a subsequent approximation will overwrite any manually input values so you will

need

to override the approximation each time it is performed.

Limitation:

RISA

2D will currently neglect the influence of adjoining framing members when those members are connected at a joint

that also has degrees of freedom restrained by boundary conditi

ons.

For example, suppose a column and beam member

connect at a joint that is restrained for translation in both directions (I.e. the joint is “pinned”).

The K factor approximation

will neglect the beam member when it calculates the K factor for the colu

mn and visa

versa.

The effect will be that the ends

of the members at that joint will be seen as “pinned” and not “fixed” for the K

factor approximation.

Sway Flags

The

Sway Flags

indicate whether the mem

ber is to be considered subject to sidesway for bending

in and out of plane

The

Out sway

field is for

out of plane

bending and the

In sway

field is for

in plane bending

Click on the field to check the box

and indicate that the member is subject to sway f

or that particular direction, or leave the entry blank if the member is braced

against sway.

These sway flags influence the calculation of the K Factors as well as the Cm.

Concrete

Design

General Reference Manual

Cm–Equivalent Moment Correction Factor

The

Cm Coef

ficients

are described in Section 10.12.3.1 of ACI code.

Cm-out

is for bending

out of plane

and

Cm-in

is for

bending

in plane

If these entries are left blank they will be automatically calculated.

In the ACI design code, the Cm values are only applicabl

e for non

sway frames. Therefore, this value will be ignored unless

the corresponding sway flag is checked.

Flexural and Shear Rebar Layout

The user may choose to manually create the reinforcement layout for t

he column.

This must be done if the user wishes to

take advantage of bundled bars, multiple layers of reinforcement, or an unequal number of bars per face.

See the section on

the Concrete Database and

Rebar Layouts

for more i

nformation.

If 'Default' is specified, then the program will design for an

equal number of bars in each face of the rectangular column and may vary that reinforcing based on ACI minimums,

maximums and the moment and shear demand at each section along the

span.

Icr Factors (Cracked Moment of Inertia Factors)

The

Icr Factor

is used to reduce the bending stiffness of concrete columns per section 10.11.1 of the ACI code. If this e

ntry

is left blank, default values of 0.35 for beams and 0.70 for columns will be used.

Note



The

Icr Factor

will be ignored if the

“Use Cracked Stiffness”

box is not checked on the

Concrete

tab of the

Global Parameters

dialog.

Service Level Stiffness

Due to cracking and material non

linearity, modeling the stiffness of concrete members is more complex than it is for steel or

wood members.

For typical applications, ACI section 10.11.1 require

s that member stiffness be reduced to account for the cracking that

occurs when a member is subjected to ultimate level loads. As described in the previous section, RISA uses the

Icr Factor

account for this stiffness reduction. However, for service leve

l analysis, the level of cracking will be significantly less.

Therefore, the stiffness used in your analysis should be representative of the reduced loading and reduced cracking. Per the

ACI commentary (R10.11.1), the program will account for this increase

d stiffness by applying a factor of 1.43 to the cracked

section properties for any load combination that has the

“Service Load”

flag checked on the

Design

tab of the

Load

Combinations Spreadsheet

Note



When the

“Use Cracked Stiffness”

box is not checked on

the

Concrete

tab of the

Global Parameters

settings,

the program will use the un

cracked section for both service level and ultimate level member stiffness.

Concrete Design Parameters

Beams

The

Concrete Beam

tab o

n the

Members Spreadsheet

records the design parameters for the code checks of concrete beams.

These parameters may also be assigned graphically. See

Modifying Member Design Parameters

to learn how to do this.

The following parameters can be defined for each concrete member.

Concrete

Design

RISA

2D v10

Label

You may assign a unique

Label

to all of the members. Each label must be unique, so if you t

ry to enter the same label more

than once you will get an error message.

You may relabel

at any time with the

Relabel

options on the

Tools

menu.

Shape

The member

Shape

or Section Set is reported in the second column.

This value is listed for reference onl

y and may not be

edited as it is dictated by the entry in the Section/Shape column on the

Primary

tab.

Length

The

member

Length

is reported in the

third

column.

This value may not be edited as it is dependent on the

member end

coordinates

listed on the

imary Data

tab. It is listed here as a reference only.

Effective Widths (B

eff Left and B

eff Right)

B-eff Left

and

B-eff Right

are the effective widths of the slab for T

beam and L

beam design. See the section on

T-beam &

L-bea

m Sections

below for more information on Effective widths.

Flexural and Shear Rebar Layout

The user may choose to manually create the reinforcement layout for the beam.

This must be done if the user wishes to

take

advantage of compression steel, or multiple layers of reinforcement.

See

Concrete Database

Rebar Layouts

for more

information.

If 'Default' is specified, then the program will design for one layer of reinforcing and may v

ary that reinforcing

based on ACI minimums, maximums, and the moment and shear demand at each section along the span. If you define your

own rebar layout, and compression reinforcement is defined, then the program will consider the compression reinforcemen

in the analysis.

Icr Factors (Cracked Moment of Inertia Factors)

The

Icr Factor

is used to reduce the bending stiffness of concrete beams per section

10.11.1 of the ACI code. If this entry is

left blank, default values of 0.35 for beams and 0.70 for columns will be used.

Note



The

Icr Factor

will be ignored if the

“Use Cracked Stiffness”

box is not checked on the

Concrete

tab of the

Global Parameters

dia

log.

Service Level Stiffness

Due to cracking and material non

linearity, modeling the stiffness of concrete members is more complex than it is for steel or

wood members.

For typical application

s, ACI section 10.11.1 requires that member stiffness be reduced to account for the cracking that

occurs when a member is subjected to ultimate level loads. As described in the previous section, RISA uses the

Icr Factor

account for this stiffness reduct

ion. However, for service level analysis, the level of cracking will be significantly less.

Therefore, the stiffness used in your analysis should be representative of the reduced loading and reduced cracking. Per the

ACI commentary (R10.11.1), the program

will account for this increased stiffness by applying a factor of 1.43 to the cracked

section properties for any load combination that has the

“Service Load”

flag checked on the

Design

tab of the

Load

Combinations Spreadsheet

Note



When the

“Use Cracked St

iffness”

box is not checked on the

Concrete

tab of the

Global Parameters

settings,

the program will use the un

cracked section for both service level and ultimate level member stiffness.

Concrete

Design

General Reference Manual

T-beam & L

beam Sections

T-beams

and

L-beams

may be specified by assigning effective slab widths and slab thicknesses for the left and right side of

the beam on the

Concrete Beam

tab of the

Members Spreadsheet

These modifications may also be made graphically via

the

Modify Propert

ies

tab of the

Draw Members

tool.

RISA

-2Dwill automatically trim the effective slab widths,

B-eff Left

and

B-eff Right

, to the maximum values indicated in

sect

ions 8.10.2(a) and 8.10.3(a) & (b) of ACI 318 if the value entered by the user is greater than that allowed by the code.

should be noted that RISA

-2Ddoes not check sections 8.10.2(b) and 8.10.3(c) of ACI 318 because no adjacent framing

checks are perfo

rmed.

If the values of either

B-eff Left

B-eff Right

are left blank, a value of zero will be assumed, indicating no additional slab

width beyond 1/2 the beam width on that side.

Note



B-eff Right corresponds to the positive local z

axis of the beam. Subs

equently, B

eff Left corresponds to the

negative local z

axis.

Parabolic vs. Rectangular Stress Blocks

You can specify whether you want your concrete design to be performed with a rectangular stress block, or with a mo

accurate parabolic stress block. While most hand calculations are performed using a rectangular stress block, the parabolic

stress block is more accurate. In fact, most of the PCA design aids are based upon the parabolic stress distribution. A good

refe

rence on the parabolic stress block is the PCA Notes on ACI 318

99.

Concrete

Design

RISA

2D v10

Biaxial Bending of Columns

You can specify whether you want your column design to be performe

d by using

Exact Integration

, or by using the

PCA

Load Contour Method

. While most hand calculations are performed using the Load Contour Method, this method is merely

an approximation based on the uniaxial failure conditions and the Parme Beta factor. In c

ontrast, the Exact Integration

method uses the true biaxial strain state to design the member. A good reference on the Load Contour Method is chapter 12

of the PCA Notes on ACI 318

99.

Concrete

Design

General Reference Manual

Limitations

General

Torsion

–

Concrete design does not take into account torsional forces in beams

or columns

. A message is shown in the detail

report to remind you of this.

You can turn the

warning messages off on the

Concrete

tab of the

Global Parameters Dialog

Beam Design

–

Beams are not designed for weak axis y

y bending, weak axis shear, or axial forces. A message is shown in

the detail report to remind you of this.

You can turn the war

ning messages off on the

Concrete

tab of the

Global Parameters

Dialog

Beams currently do not consider any compression steel in the calculation of the moment capacity. Beam "skin

reinforcement" per the requirements of ACI 10.6.7 for beams with "d" greater

than 36" is currently not specified by the

program. The provisions in ACI 10.7 for deep beams are not considered.

Column Design

–

Columns with biaxial moment and no axial load will currently be designed using the

PCA Load Contour

Method

even if Exact Integ

ration is selected on the Global Parameters dialog. This is shown on the detail report.

Limitations

ACI

Shear Design

–

The shear strength of the concrete alone is limited to the standard 2*sqrt (f'c) equation from ACI 318 section

11.3.1.1 and does not u

se the more detailed calculations of section 11.3. Also note that we use provision 11.3.1.3 which states

"For members subject to significant axial tension, shear reinforcement shall be designed to carry total shear unless a more

detailed analysis is made u

sing 11.3.2.3." The program does not use this more detailed analysis.

Shear Design

–

The shear strength of the concrete does not consider the provisions of 11.2 regarding lightweight concrete.

Deep Beam Design

–

We do not consider provisions from ACI 318

section 11.8 in design.

Limitations

Canadian Code

Concrete Stress Profile

–

Concrete stress strain curve (parabolic) is assumed same as PCA method for the Canadian codes.

Bi-Axial Bending

The program uses the simplified uniaxial solution provided in

the Canadian specification rather than

performing a complete biaxial condition.

Mid-Depth Flexural Strain for Shear Design

The program uses the simplified code equation for

with the moment and

shear at the section taken from the envelope diagrams. The

maximum

for each span is conservatively assumed for the

entire span.

Limitations

Australian and New Zealand Codes

Concrete Stress Profile

–

Concrete stress strain curve (parabolic) is assumed same as ACI for the New Zealand and

Australian codes.

acked Sections

–

Icracked is only considered for US and Canadian codes. Icracked for the Australian and New Zealand

codes is ignored and the program uses the full gross properties.

Neutral Axis Parameter

–

Ku in AS code

is always assumed to be less than

0.4.

Rebar Spacing

–

NZS and AS codes: max spacing of rebar (beam) is 300 mm and minimum spacing is one bar diameter or

25mm whichever is bigger.

Shear Strength in Beams

–

In AS code, when calculating the shear strength of a beam β2, β3 are always assumed to be

unity.

This is always conservative for beams will little axial load, or beams in compression.

But, may be unconservative for

members subjected to significant net t

ension.

Bi-Axial Bending

–

The New Zealand code does not appear to give a

simplified method for solving biaxial column design.

Therefore, the PCA load contour method is being used instead.

Shear Tie Spacing

–

Column/beam shear tie spacing is based on (a)

and (c) of NZS 9.3.5.4 :1995.

Development Length

–

Development length in NZS is based on NZS 7.3.7.2 where αa is conservative assumed to be 1.3

(top bars) for all cases.

For the AS code, it is assumed that K1=1 and K2=2.4 in clause 13.1.2.1 of AS 3600:2001.

Concrete

Design

RISA

2D v10

Slender Column Calculations

–

EI is assumed to

be equal to 0.25EcIg (with βd =0.6) in slender column calculations in AS

and NZS codes (like in ACI).

Limitations

British

Concrete Stress Profile

–

Concrete stress strain curve (parabolic) is taken from the British specification.

Cracked Sections

–Icracked is only considered for US and Canadian codes. Icracked for the British code is ignored and the

program uses the full gross properties.

Bi-Axial Bending

–

The program uses the simplified uniaxial solution provided in the British specification rather

than

performing a complete biaxial condition.

Limitations

Euro

Concrete Stress Profile

–

Concrete stress strain curve (parabolic) is taken from the EuroCode specification.

Cracked Sections

–

Icracked is only considered for US and Canadian codes. I

cracked for the EuroCode is ignored and the

program uses the full gross properties.

Bi-Axial Bending

–

The program uses the simplified uniaxial solution provided in the EuroCode rather than performing a

complete biaxial condition.

Limitations

Indian

Conc

rete Stress Profile

–

Concrete stress strain curve (parabolic) is taken from the Indian specification.

Cracked Sections

–

Icracked is only considered for US and Canadian codes. Icracked for the Indian code is ignored and the

program uses the full gross

properties.

Bi-Axial Bending

–

The program uses the simplified uniaxial solution provided in the Indian specification rather than

performing a complete biaxial condition.

Limitations

Saudi Code

Concrete Stress Profile

–

Concrete stress strain curve (

parabolic) is assumed to be the same as the ACI code.

Shear Strength

–

The shear strength is based on 11.3.1.1 and does not include the more detailed provisions of section

11.3.1.2.

Yield Strength of Shear Ties

The yield strength of shear ties is not a

llowed to exceed 420MPa.

Shear Tie Spacing

Minimum spacing of shear ties is set to 50mm

Bi-Axial Bending

–

Both the Exact Integration and the PCA Load Contour methods for bi

axial bending are supported in the

Saudi code.

Special Messages

In some instances code checks are not performed for a particular

member

A message is usually shown in the

Warning Log

and

Detail Report

explaining why the code check was not done. There are also instances where a code check is performed,

but the results may be suspect as a provision of the design code was violated. In these cases, results are provided so that t

hey

can be examined to find the cause of the problem. Following are the messages that may be seen.

No Load Combinations for Concre

te Design have been run.

None

of the load combinations that were run had the

Concrete Design

box checked on

the

Design

tab of

the

Load

Combinations Spreadsheet

. Since there are no concrete design specific load combinations, there are no results or force

agrams to show.

Concrete

Design

General Reference Manual

Warning: No design for spans with less than 5 sections.

Certain very short spans in physical members can end up with less than 5 design sections. No design is attempted without at

least 5 sections because maximum values may be missed and an

un-conservative design may result.

Warning: No design for spans less than 1 ft.

Certain very short spans in physical members can end up with lengths less than 1 foot. No design is attempted for these

sections.

Warning: Member is slender and can sway, but

P-Delta Analysis was NOT run.

Slender sway members need to be run with the P

Delta option turned on to account for secondary forces and moments. In

some situations, a preliminary design without P

Delta is useful and so a design is performed and this warnin

g is shown to

remind you to run the final analysis including P

Delta effects. Alternately, if you’re using the redesign feature, the next

suggested column may resolve this issue if it’s not slender.

Warning: Slender Compression Failure (Pu > .75Pc). No Sle

nder calculations done.

Since RISA

2D allows you to specify a starting column size, it’s possible that for slender columns under substantial axial

load you'll exceed the critical buckling load used in the slenderness equations in ACI 10.12.3. Design result

s are still shown

so the suggested shapes can be used to pick a new suggested column size that will not have this problem. Note that the design

results shown are NOT valued because the slender moment effects have NOT been considered.

Warning: KL/r > 100 fo

r this compression member.

See ACI99 10.10.1

Members that violate the KL/r limit still have design results calculated and shown. If you’re using the redesign feature, the

next suggested shape should resolve this problem.

Warning: Exact Integration selecte

d but PCA method used

This message is shown when you've requested the

Exact Integration

option on the

Global Parameters Dialog

, but we

weren't able to converge a solution for the column in question. When Exact Integration does not converge, the

PCA Method

is used instead to give an idea of the demand vs. the capacity.

Warning: PCA Method Failed. Axial Load > Axial Capacity.

One of the limitations of the

PCA Method

is that it requires the column being checked to have a greater axial capacity than

the axial d

emand.

Since RISA

2D allows you to set a starting size, it’s possible that the demand may be greater than the

capacity. In this case a very rough estimate of the capacity is calculated by using the independent moment capacity about

each axis considering th

e axial load. The resulting code check value is then based on the combined demand vector over the

combined capacity vector and will always be greater than 1.0. The purpose of the results in this case is to show the column

failed, not to give an accurate es

timate of the over

demand. The redesign feature will suggest a larger shape to resolve this

issue.

Warning: The shear tie spacing does not meet the code Minimum Requirement

This warning is stating that either minimum spacing or strength requirements are no

t being met for the shear reinforcement in

the concrete member.

Concrete

Design Results

RISA

2D v10

Concrete

Design Results

You can access the

Concrete Results Spreadsheets

by selecting the

Results Menu

and then selecting

Members

Design

Results

Concrete Reinforcing

Unlike wood and steel, concrete results are different for beams and columns so they each

get their own results spreadsheet.

Note

also

that concrete

results are always based on envelope results

, even if you've run a

batch solution

For beam flexural design, the required bars are based on the envelope moment diagrams.

For column flexural design, the

required bars for each load combination are calculated

at various sections for the moments and axial forces at those sections.

The required bars for all load combinations are then enveloped.

For

both

beam

and column

shear steel design, the required

bars are based on the enveloped shear force diagrams.

Beam Re

sults

Beam results are shown in the three

following spreadsheets:

Design Results

Beam Bending Reinforcement

, and

Beam

Shear Reinforcement

Design Results Spreadsheet

The

Design Results Spreadsheet

shows the governing m

aximum code check for the top and bottom of the beam for all

spans.

These top and bottom code checks,

UC Max Top

and

UC Max Bot

, are based on

the top/bottom moment capacities and

maximum top/bottom moment. Currently the moment capacity is based only on the tension steel (NO compression steel is

considered in the capacity calculation). The governing maximum shear check for all spans,

Shear UC

, i

s also shown. The

capacities shown are only for the governing section. Capacities for each span, as well as beam reinforcement detailing

diagrams, may be viewed on the

Detail Report

Beam Bending Reinforcement Spreadsheet

The

eam Bending Reinforcement Spreadsheet

records the top and bottom flexural reinforcement steel required for the

left, middle, and right locations of each beam. This spreadsheet may be accessed by selecting

Members

Concrete

Reinforcing

on the

Results Menu

and the results are listed on the

Beam Bending

tab.

The

Member

column lists the beam label.

The

Shape

column displays the beam size.

When no adequate member could be found from the available shapes list, this

field will display the text "not designed". Consider re

framing, relaxing the desi

gn requirements (see

Design Optimization

or adding more shapes to the available Redesign List (see

Appendix A

–

Redesign Lists

).Concrete

Design Results

General Reference Manual

The

Span

column displays the span number corresponding to th

e reinforcement sections listed. Span '1' is the span beginning

at the "start" of the beam and subsequent spans are numbered '2', '3', '4', and so forth moving from the "start" to the "end"

the beam.

The program assumes that the moment diagrams for all

beam spans have two or fewer points of inflection. Therefore, each

span is broken into

Left, Middle, and Right Reinforcement Sections

for flexural steel layout. Each section is further broken

into

Top and Bottom Reinforcement Sections

. Note that a beam may

have only two or even one reinforcement section. In

this case, the other reinforcement sections would be left blank in this spreadsheet.

The

Left Top

Left Bot

Mid Top

Mid Bot

Right Top

, and

Right Bot

entries record the number and size of flexural

rein

forcement bars that are required in each of the six

Reinforcement Sections

. The first number indicates the number of

parallel reinforcement bars in that section. The second number, preceded by the '#' sign, indicates the size of reinforcement

bars used.



Only reinforcement bars selected by the program are listed in this spreadsheet. If a custom rebar layout is used for

a particular beam, all six reinforcement section entries will be left blank.



Longitudinal reinforcement bars are assumed to be in a

sing

le layer

at the top and/or bottom of the member.



Longitudinal reinforcement bars for the left and right sides of adjacent spans have been "smoothed" such that the

larger steel area is used for both sides.

Beam Shear Reinforcement Spreadsheet

The

Beam Shear

Reinforcement Spreadsheet

records the shear reinforcement ties required in each shear region of each

beam. This spreadsheet may be accessed by selecting

Members

Concrete Reinforcing

on the

Results Menu

and the

results are listed on the

Beam Shear

tab.

The

Member

column lists the beam label.

The

Span

column displays the span number corresponding to the shear regions listed. Span '1' is the span beginning at the

"start" of the beam and subsequent spans are numbered '2', '3', '4', and so forth moving from the "start" to the "end" of the

beam.

Each beam's shear reinforcement layout is broken into either two or four

Shear Reinforcement Regions

. The user can

control whether the program uses '2' or '4' regions from the

Concrete

tab of the

Global Parameters Dialog

. The program

will try to group the

required shear ties/stirrups into two or four regions and will allow for a middle region to have no shear

reinforcement if the shear force is lower than that for which the code requires shear reinforcement.

The

Region 1

Region 2

Region 3

, and

Region 4

ntries record the number, size, and spacing of shear reinforcement

ties/stirrups that are required in each of the

Reinforcement Regions

. The first number of each entry indicates the total

number of ties/stirrups that are required in that region of the beam

span. The second number, proceeded by the '#' sign,

indicates the size of reinforcement bars used. The third number, proceeded by the "@" symbol, indicates the spacing of the

ties/stirrups in that region of the beam span.

Note

Concrete

Design Results

RISA

2D v10



If '2' shear regions are sel

ected on the

Concrete

tab of the

Global Parameters Dialog

, the Region 2 and Region

3 entries in this spreadsheet will be left blank.



The concrete code checks are only performed at the sections where the internal forces are calculated.

The number

of interna

l force calculations is based on the setting in the

Global Parameters

dialog.

Normally, this is acceptable

for design and analysis.

However, it is possible for the design locations (face of support for moment and "d" from

the fa

ce of support for shear) to be located far enough away from the nearest internal force location that it could

affect the code check results. If this happens, it may be advisable to use a larger number of internal sections.

Or,

the user may be forced to cal

culate the maximum Vu and Mu themselves.

Column Results

Column results are shown in the three following spreadsheets:

Design Results

Column Bending Reinforcement

, and

Column Shear Reinforcement

Design Results Spreadsheet

The

Design Results Spreadsheet

ows the governing maximum code check for the column for all spans.

The governing maximum shear check for all spans is also shown.

The governing load combination

for the governing code

check is shown because the column capacity is based upon the actual moments and axial forces for that load

combination.

The capacities shown are only for the governing section. Capacities for each span, as well as beam

reinforcement

detailing diagrams, may be viewed on the

Detail Report

Column Bending Reinforcement Spreadsheet

The

Column Bending Reinforcement Spreadsheet

shows the perimeter flexural reinforcement steel required in each span

of each column

This spreadsheet may be accessed by selecting

Members

Concrete Reinforcing

on the

Results Menu

and the results are listed on the

Column Bending

tab.

The

Column

field displays the column label.

The

Shape

column displays the physical column or lift size. When no adequate member could be fo

und from the available

shapes, this field will display the text “not designed”. Consider re

framing, relaxing the design or deflection requirements

(see

Design Optimization

), or adding more shapes to the available Redesign

List (see

Appendix A

–

Redesign Lists

The

Span

column displays the span number corresponding to the perimeter reinforcement listed. Span '1' is the span

beginning at the

"start"

of the column and subsequent spans are numbe

red '2', '3', '4', and so forth moving from the

"start"

the

"end"

of the column.

The

Perim Bars

column records the number and size of perimeter longitudinal reinforcing bars. The first number indicates

the total number of longitudinal bars in that span.

The second number, preceded by the '#' sign, indicates the size of the

reinforcement bars used.

Concrete

Design Results

General Reference Manual

Note



Only reinforcement bars selected by the program are listed in this spreadsheet. If a custom rebar layout is used for

a particular column, the

Perim Bars

entry will be left blank.



Longitudinal reinforcement bars are assumed to be uniformly arranged around the perimeter of the column for

both rectangular and round column sections.



A minimum of 6 bars will be used in round column sections.



Longitudinal reinfo

rcement bars for the bottom and top sides of adjacent spans have been "smoothed" such that

the larger steel area is used for both sides.

Column Shear Reinforcement Spreadsheet

The

Column Shear Reinforcement Spreadsheet

shows the shear reinforcement ties re

quired in each shear region of each

column. This spreadsheet may be accessed by selecting

Members

Concrete Reinforcing

on the

Results Menu

and the

results are li

sted on the

Column Shear

tab.

The

Column

field displays the column label.

The

Span

column displays the span number corresponding t

o the shear regions listed. Span '1' is the span beginning at the

"start"

of the column and subsequent spans are numbered '2', '3', '4', and so forth moving from the

"start"

to the

"end"

of the

column.

Each column's shear reinforcement layout is broken int

o either two or four

Shear Reinforcement Regions

. The user can

control whether the program

uses '2' or '4' regions from the

Concrete

tab of the

Global Parameters

dialog. The program will

try to group the required shear ties into 2 or 4 regions. Unlike beam

s, columns cannot have a zero shear steel region. Note

also that columns in tension receive NO shear capacity from the concrete.

The

Region 1

Region 2

Region 3

, and

Region 4

entries record the number, size, and spacing of shear reinforcement

ties/stirrup

s that are required in each of the

Reinforcement Regions

. The first number of each entry indicates the total

number of ties/stirrups that are required in that region of the column span. The second number, proceeded by the '#' sign,

indicates the size of re

inforcement bars used. The third number, proceeded by the "@" symbol, indicates the spacing of the

ties/stirrups in that region of the column span.

Note



If '2' shear regions are selected on the Concrete tab of the Global Parameters dialog, the Region 2 and

Region 3

entries in this spreadsheet will be left blank.

Concrete Detail Reports

The

Concrete Detail Reports

allow you to see the overall force

, stress, and deflection

ate for any particular

member

. Detail

reports for concrete

members

are not based on individual load combinations

as they are for steel or wood members

. Instead,

they are based on an envelope of the solved load combinations.

Concrete columns are the excepti

on to this in that the

columns are solved for all load combinations and then the resulting required steel is enveloped.

The detail reports for

concrete Column member types are also different than those for concrete Beam member types in terms of the design

information that is shown below the force diagrams.

Concrete

Design Results

RISA

2D v10

Detail reports for concrete

members

can, and often do, go more than one page in length due to the large amount of

information that must be displayed for concrete design. One reason for this is that RISA

-2D

figures out the number of spans

for concrete beams

and columns

based on the number of internal supports, thus one physical member may have several spans

that all must be reported.

Beam Detail Reports

The image below is the first portion of a detail repor

t for a concrete beam

member

showing the member information,

warnings, force diagrams, code checks, and span information.

You

can tell the

Member Type

by looking at the black title in the upper left corner next to the red member label. This title

will always show the member type (Beam

, Column, HBrace, VBrace

If the member type is 'None', this title will be

displayed as 'Member

The

Member Information

in the text above the force diagrams shows basic member information as well as the

Concrete

Stress Block

type used in the solution

, whether

Cracked Sections

were used for the nominal design, and the

Cracked 'I'

Factor

that was use

d for that member

Concrete

Design Results

General Reference Manual

The next section of the detail report contains the

Member Force Diagrams

The diagrams shown are envelope diagrams of

all solved load combinations.

Any

Unused Force Warnings

or critical

Design Warnings

will be shown directly below the

orce diagrams in the detail report. An enlarged interactive member force diagram can be accessed by clicking on the desired

diagram.

Each enlarged diagram will also have a slider bar at the bottom of the window for checking forces at all locations along the

member. There is also an

Abs Max

button that will jump the slider

bar to the absolute maximum value in the diagram.

Note

that once an enlarged diagram is opened, diagrams for other forces may be accessed via the pull down menu on the left.

The

Code Check Information

directly below the force diagrams is a summary of the

governing checks for bending and

shear, their location, and the section capacities at those locations. Separate bending checks for the most critical top and m

ost

critical bottom condition are given.

Gov Muz Top

and

Gov Muz Bot

represent the governing ultim

ate moment in the top

and bottom of the beam respectively.

Gov Vuy

represents the governing ultimate shear along the local y axis of the beam.

The values

phi*Mnz Top

and

phi*Mnz Bot

represent the nominal moment strength in the top and bottom of the beam

spectively, reduced by the appropriate

Strength Reduction Factor

Phi

, as indicated in the code.

Likewise, the value

phi*Vuy

represents the nominal shear strength in the beam, reduced by the appropriate Phi Factor.

There is also general concrete, reinforce

ment, and bar cover information about the section provided which you would need if

you were doing a hand check.

Concrete Type

(Normal Weight vs Light Weight) is automatically determined from the

Concrete Weight

density per the ACI code. The

E_Concrete

valu

e shown here is either the value entered on the

Concrete

tab of the

Materials Spreadsheet

or is the calculated value based on the given f’c and weight density (if the 'E' value was left

blank on the Materials Spreadsheet).

The

Span Information

gives the st

art and end of each span centerline within the member, as well as the distance from the

column

centerline to the face of the

column

for each end of the span.

The next portion of the detail report shown below contains detailed information for the placement

of the

Bending Steel

and

the

Bending Span Results

for each span. The bending capacity for the governing section in each span is shown as

Mnz

, the

nominal moment strength.

Rho Min

and

Rho Max

are the minimum and maximum required reinforcement ratios at each

location.

These values are based on the minimum and maximum reinforcing requirements for flexural members as described

in ACI 318 sections 10.5.1 and 10.3.3/10.3.5 respectively.

Rho

is the ratio of reinforcement corresponding to the area of steel

provided

at each location,

As Prvd

The

As Req

value is the area of steel required at each location.

Note:



Per ACI 318

05 Section 10.5.3, the reinforcement ratio (ρ) chosen by the program can be less than ρ

min

when A

Provided exceeds A

Required by more than 33%

Concrete

Design Results

RISA

2D v10

The next portion of the detail report, shown above, contains detailed information for the placement of the

Shear Steel

and the

Shear

Span Results

for each span. Shear results are shown by region within each span. The number

of regions used is a

function of the shear diagram, with the maximum number of regions being taken from the

Shear Regions

setting on the

Concrete

tab of the

Global Parameters Dialog

The number, size, and spacing of reinforcing bars is given for each regio

Also indicated is the nominal shear strength,

, in each region. The portion of the nominal shear strength provided by the

concrete and the steel,

andVsrespectively, is given for each region.

The area of steel required,

As Reqd

, and the area of

teel provided,

As Prvd

, are also given for each shear region and are reported as 'area of steel per unit dimension', i.e. in

/in

or mm

/mm.

It should be noted that the values for

andVngiven in this section of the detail report are the UNREDUCED nomina

capacities of the member at each span/region.

The actual design capacities would be obtained by multiplying these values by

their respective

Phi Factors

indicated in the code.

Concrete

Design Results

General Reference Manual

The last section of the detail report shows the

Beam Reinforcement Detailing D

iagrams

The

Rebar Detailing

portion of

the report shows elevation views of the beam complete with top and bottom flexural reinforcement indicated for the left,

middle, and right portions of each span.

The number and size of bars required in each section i

s indicated on the top middle

of each drawn bar.

The required length of each bar is indicated on the bottom middle of each drawn bar in

parenthesis.

Development lengths are shown in parenthesis at one end of each bar and is represented by a dashed line.

Forbars at the ends of the beam, hook lengths are given in addition to the development lengths and are shown in brackets.

The values shown at the bottom corner of each span indicate the distance from the start of the beam to the face of a

support.

Flexural

bars at the ends of the beam are measured beginning at the face of the support and bars at intermediate

supports are measured to the center of the support.

The number, size, and spacing of shear reinforcement is also indicated below each span in the corres

ponding shear

region.

Each shear region is indicated by vertical lines at the bottom of the beam.

The

Cross Section Detailing

port

ion of the report shows cross sectional views for the start, middle, and end of each beam

span.

The number and size of flexural bars for each cross section are shown as well as the orientation of the shear

ties/stirrups.

The clear cover to each stirrup for

the top and sides is shown.

The overall beam dimensions for each span are

indicated on the 'Start' cross section.

Column Detail Reports

The image below is the first portion of a detail report for a concrete column member showing the member information,

rnings, force diagrams, code checks, and span information. As can be seen, the concrete column results are very similar to

the beam results with just a few additions and differences.

Concrete

Design Results

RISA

2D v10

You can tell the

Member Type

by looking at the black title in the upper left corner next to the red member label. This title

will always show the member type (Beam, Column, HBrace, VBrace). If the

member type is "None", this title will be

displayed as "Member".

The

Member Information

in the text above the force diagrams shows basic member information as well as the

Concrete

Stress Block

type used in the solution, whether

Cracked Sections

were used

for the nominal design, and the

Cracked 'I'

Factor

that was used for that member.

The next section of the detail report contains the

Member Force Diagrams

The diagrams shown are envelope diagrams of

all solved load combinations.

Any

Unused Force Warnings

or critical

Design Warnings

will be shown directly below the

force diagrams in the detail report. An enlarged interactive member force diagram can be accessed by clicking on the desired

diagram. For more information, see

Beam De

tail Reports

The

Code Check Information

below the force diagrams is a summary of the governing checks for bending and shear, their

location, and the section capacities at those locations.

Gov Pu

represents the governing ultimate axial load in the

column.

Gov Mu In

and

Mu Out

represent the governing ultimate moment in and out of plane.

Gov Vu In

and

Vu Out

represent the governing ultimate shear in and out of plane.

There is also general concrete, reinforcement, and bar cover information about the section p

rovided which you would need if

you were doing a hand check.

Concrete Type

(Normal Weight vs Light Weight) is automatically determined from the

Concrete Weight

density per the ACI code. The

E_Concrete

value shown here is either the value entered on the

Con

crete

tab of the

Materials Spreadsheet

or is the calculated value based on the given f’c and weight density (if the 'E' value was left

blank on the Materials Spreadsheet).

Concrete

Design Results

General Reference Manual

Note:



When solving using the PCA Load Contour method, P

will always equal P

. This

represents the axial value at which

the controlling slice of interaction diagram was taken. The bending check is taken as the following equation, which is

derived from the PCA

Notes on ACI 318

99, Chapter 12.



When solving using the Exact Integration method, a worst

case combination of P

, Muy, and M

is determined. A

straight line is essentially drawn between the origin of the interaction diagram, and this coordin

ate within the 3D

interaction diagram. The bending check is taken as the length of that line, divided by the distance from the origin to

the intersection of that line and the interaction diagram. For this reason the ratios (P

/φPn), (M

/φMn) are all equal to

the bending check.

Concrete

Design Results

RISA

2D v10

The next portions of the detail report shown above contain the

Column I

nteraction Diagrams

for the column member and

the

Span Information

Column Interaction Diagram

for uniaxial bending is shown for each axis of the column.

These diagrams plot the

unreduced nominal strengths

P vs. M

for the corresponding column local axi

If the column only has bending about one axis

there will be only one interaction diagram shown.

For columns under biaxial bending there is also a diagram which plots the unreduced nominal moments strengths

Mz vs. My

at the governing ultimate axial load,

The last diagram is for the biaxial bending condition where the exact integration

method is used and shows the interaction surface plotted at the angle of applied load (Pu, Muy, Muz).

This last diagram is

only shown when the

Exact Integration Method

used.

The

Span Information

section shows the length of each span and the distances from the centerline of each support to the

face of each support.

Concrete

Design Results

General Reference Manual

The last portion of the report shown above contains the sections pertaining to the axial, bending, and shear results as well

the longitudinal and shear reinforcement.

The

Column Steel

section indicates the longitudinal reinforc

ement in each span as well as the governing load combination

and location.

The ultimate axial load,

, and the ultimate moments,

Mu out

and Mu in, are also given for each span.

The

Axial Span Results

show the strength reduction factor,

Phi_eff

, used for e

ach span.

The axial capacities for each span

are shown as

, the nominal axial strength, and

, the nominal axial strength with zero eccentricity.

The area of

longitudinal reinforcement provided in the column is listed as

As Prvd

and the ratio of As Prvd

to the gross cross sectional

area of the column is listed as

Rho Gross

The

Bending Span Results

show the calculated eccentricities,

ecc. In

and

ecc. Out

, due to the ultimate moment in or out of

plane divided by the ultimate axial load.

The neutral axis d

epth for bending in and out of plane are listed as

NA In

andNAConcrete

Design Results

RISA

2D v10

Out

respectively.

These neutral axis locations are always given with respect to the geometric center of the column. Also

shown in this section are the unreduced nominal moment capacities,

Out

and

Mn In

, for each span of the column.

If the

PCA Load Contour Method

is used,

Mno Out

and

Mno In

are given, representing the maximum allowable moment for

uniaxial bending at the nominal axial strength,

(see

Biaxial Bendi

ng of Columns

If the

Exact Integration Method

used, these values will be left blank.

The

Sheer Steel

section of the report shows each span of the column broken into one or more shear regions and the number,

size, and spacing of shear stirrups require

d in each of those regions is given.

The shear design for columns is the envelope of

all the shears for both directions.

The

In Plane and Out Plane Shear Span Results

show the nominal shear strength,

Vn In

and

Vn Out

, in each shear region

of the column fol

lowed by the nominal shear strengths of the concrete,

Vc In

and

Vc Out

, and the nominal shear strengths of

the steel,

Vs In

and

Vs Out

The area of shear reinforcement required in each shear region of the column is shown as

As In

Reqd

and

As Out Reqd

The

area of shear reinforcement provided in each shear region of the column is shown as

Prvd

Shear demand and concrete capacity are shown for both directions, but only one design of shear ties is used.

Thus the

As_reqd may vary for each side, but the As_

prvd will always be the same.

Magnified Moments / Slenderness Effects

The

Slender Bending Span Results

give the ultimate moments

in and out of plane

amplified for the eff

ects of member

curvature,

Mc Out

and

Mc In

These values will be left blank for spans that do not meet the criteria for slender columns in

the specific direction.

Also shown in this section are the values

KL/r

in and out of plane

, followed by the equivalen

t moment

correction factors

Cm Out

and

Cm In

The unbraced lengths of the column for each span and each direction,

Lu Out

and

Lu In

, are given as well.

For Non

Sway frames, the assumption is that EI = 0.25*Ec*Ig. This is equivalent to setting Bd to 0.6 in

ACI equation 10

13.

For sway frame columns with a KL/r value greater than 22, the moment amplification is applied to the total moment rather

than the "non

sway" portion of the moment.

Warning Log Messages will be produced when the following occurs:



If t

he KL/r for the column exceeds 100 per Section 10.11.5 of ACI 318.



If a slender member is classified as being part of a Sway frame, but a P

Delta analysis was NOT performed. For sway

frames this P

Delta requirement applies anytime the slenderness ratio

/r exceeds 22.

Customizing RISA

General Reference Manual

Customizing RISA

You may customize many of the default parameters, design and analysis options in RISA

-2D. In this way you can modify the

program so that it best suits you and your work processes. A

ll customization may be defined or redefined at any time. The

Preferences

option on the

Tools Menu

provides you control over the behavior of the software. The

Save as Defaults

feature

allows you to specify the default settings for new m

odel

files.

These features are discussed below. Custom reports may also

be defined and saved for future use. See

Printing

to learn how to build a custom report.

Save as Defaults

You may use the

Save as Defaults

feature in the following dialog boxes

by entering the default information in the dialog and

clicking the

Save as Defaults

button:

Global Parameters, Units

, and

Drawing Grids

. This wil

l cause the program to use

these settings with any new files that are then created.

Many of the spreadsheets also provide the option to save the current data as the default and every subsequent new file will

already have that data. Simply enter the data yo

u want then save it as the default by clicking on the

button. This way the

office standards that you might use in most of your models are already entered and

available in new models. This feature is

available in the following spreadsheets:

Materials

Custom Wood Species

Design Rules

Footing Definitions

and

Load

Combinations

Once you create a new file you may redefine any of the default data and settings for

that particular file so the

Save as

Defaults

feature may be used to give you a good starting point for new files but won’t hold you to those settings.

Preferences

Program options may be accessed by select

ing

Preferences

from the

Tools Menu

and are divided into the five sections

described below. Many of the preferences themselves are self

explanatory.

General Preferences

The general preferences

are straightforward. For help on an item click

and then click that item. It may be a good i

dea to

disable the

Automatically refresh…

option when working with large files or slower computers. You may also set the

backup

timing. See

Automatic Backup

to learn about the backup capabilities of RISA

-2D. The

Reset Customizat

ion

Options

button will clear all of the preferences that you have set on any of the tabs.

Customizing RISA

RISA

2D v10

Show "Starting a Model" Panel when starting a new model

–

The

New Model Dialog

will be displayed when opening the

program or selecting 'New File' from the File Menu.

Show Global dialog after loading a fil

e–Displays the Global Parameters settings automatically after loading a file.

Play the starting sound whe

n starting up the program

–

A startup sound will be played when the program opens.

Play the error sound when showing error messages

–

An error sound will be played when an error is displayed.

Automatically refresh any open windows for any data change

–

Cha

nges to the model will automatically be reflected in

all windows

–

spreadsheets and model views.

For large models you may want to limit the number of open windows or disable

this feature altogether.

Show Toolbars

–

All toolbar commands may also be found in

the menu system so if you want more work space you may

disable the toolbars.

Show Exclude Results confirmation message

–

After solving the model you may use the Exclude Feature to graphically

select items that you wish to see in the results spreadsheets,

"excluding" other results. This enables a confirmation message

warning you that some results are not shown.

Automatic backup timing

–

Automatic backup occurs at the specified interval. No backup occurs if the interval is set to

zero.

Reset Customization Op

tions

–

Choose this to return to the program defaults.

Default Region

Choose the default region for your projects.

Data Entry Preferences

To use bigger or smaller fonts in the spreadsheets you may adjust the row heights. You may also specify the number o

decimal places that are displayed. The one exception is the

Joint Coordinates

. RISA

-2Dmaintains the coordinates to 15

significant figures and the exact value is always displayed. You may use the

Tools Menu

to round off joint coordinates.

If you wish to

use a prefix with your

joint,member

, and

plate

labels, such as “

” with

joints

, you can specify the default

prefix. These prefixes may be changed as you build your model.

Row height for data spreadsheets

–

Sets the row height and font size for data spreadsheets.

Decimal places for data entry fields

–

Sets the number of decimal places to display in the data spreadsheets with a

maximum of four places.

fault prefix for JOINT labels

–

Sets the default prefix to be used in

joint

labels.

Customizing RISA

General Reference Manual

Default prefix for MEMBER labels

–

Sets the default prefix to be used in

member

labels.

Default prefix for PLATE labels

–

Sets the default prefix to be used in plate labels

Default prefix for WALL PANEL labels

Sets the default prefix to be used in wall panel labels.

Solution and Results Preferences

At solution time

RISA

-2Dfinds and locks any instabilities to allow the solution to occur. See

Stability

to learn more about

this. Rotational instabilities are commonly inconsequential and RISA

-2Dallows these instabilities to be locked wit

hout any

warning.

RISA

-2Dcan provide a warning when clearing results. To use bigger or smaller fonts in the results spreadsheets you may

adjust the row heights. You may also specify the number of decimal places that are displayed. The number of figures

splayed may not be the actual number. Behind the scenes RISA

-2Dmaintains numbers to numerous decimal places.

Lock isolated ROTATIONAL in

stabilities without notification?

–

Locks rotational instabilities at solution time without

warning.

Always warn before clearing results?

–

Verifies that results are to be cleared to edit the model.

Allow KL/r>200, l/r>300 for LRFD,CAN steel design?

–

Waiv

es the slender check for slender members.

Don't require P

Delta analysis for LRFD, CISC, etc.?

Waives the P

Delta analysis requirement for certain design codes.

Row height for Results Browsers

–

Sets the row height and font size for results spreadsheets.

Decimal Places

–

Sets the number of decimal places to display in the results spreadsheets with a maximum of four places.

Rotation Limits

–

Shows 0 for the rotation when smaller than this value.

Batch Results Display

The results of a batch solution may b

e grouped by load combination or by item. For example you

can group results for all members under each particular load combination or you can group results from each combination

under a particular member. The setting here is merely a preference. Once you h

ave solved a model you can switch back and

forth using the

Results Menu

Saving Results

–

These options let you control what is done with the results when saving a file.

Customizing RISA

RISA

2D v10

Font Preferences

The font preferences are straightforward. They c

an be used to adjust the fonts used by the spreadsheets, results browsers, and

graphics.

The font changes will affect both the on

screen displayed data and the printed data. The exceptions to this are the

spreadsheet and browser fonts which may be changed

for on

screen display but are hard

wired for printing purposes.

If the font data has be set to some unusual settings, then the user can click the

Rese

t All Fonts to Program Defaults

button

to restore the fonts to what is normally expected for the RISA program.

Printing Preferences

The printing

preferences are straightforward. For help on an item click

and then click that item. See

Printing

for more

information.

Preferr

ed orientation for graphics

–

Sets the default paper orientation for graphic printing.

Customizing RISA

General Reference Manual

Margins

–

Sets the default printing margins.

Report Preferences

–

Sets color or black and white options and header options.

File Preferences

The locations for data files, databases, temporary space, importing, and backing up may be specified separately by choosing

from the list.

Path

and current setting

–

For each file type in the list the current setting is displayed.

Click the drop down list to view

different file types.

Click the browse button to choose a different location.

Design Optimization

RISA

2D v10

Design Optimization

RISA

2D will op

timize

Hot Rolled Steel, Cold Formed Steel, Wood,

Concrete

members, masonry walls, and wood walls,

The criteria used for this optimization are the selected design code and the

Design Rules

assigned to the

member

The sizes

are chosen from a Redesign List

assigned to the member.

The

Design Rules Spreadsheet

records the parameters for the optimization. Optimization is performed for minimum weight,

taking into consideration any depth, width, rebar limitations, wall dimensions, stud spacing, etc. Note that t

he design rules

input is one large spreadsheet, thus all of your design rules will be in the same place. Masonry wall rules could be on one l

ine

with beam reinforcement on the next. Note that the dimensional rules, the reinforcement rules and the wall rule

s are all a

separate entity. They have no interaction with each other in the program. They are simply all input into the same location. F

example, your masonry wall reinforcement rules will not be influenced by concrete beam reinforcement rules (masonry

reinforcement rules are specified in the Wall Panel Editor).

You can assign the design rules graphically as you draw

members

or later as a modification. . See

Modifying Member

Properties

for more information.

Design Lists

Design List

defines a set of members that will be used in the design and optimization of a member. RISA comes with the

following Pre

Defined Design Lists.

Pre-Defined Design Lists

Material Type

Member Type

Shape Groups

Hot Rolled Steel

eams

Wide Flange

Channel

Tube

Columns

W14

W12

W10

Tube

Pipe

Cold Formed Steel

Beams

CU shapes

CS Shapes

ZU Shapes

ZS Shapes

HU Shapes

Columns

CU shapes

CS Shapes

ZU Shapes

ZS Shapes

HU Shapes

NDS Wood

Beams

Rectangular

–

Single

Design Optimization

General Reference Manual

Rectangular

Double

Rectangular

–

Triple

Round

Columns

Rectangular

–

Single

Rectangular

Double

Rectangular

–

Triple

Round

Concrete

Beams

Rectangular

Columns

Rectangul

Round

Steel Products

Beams

Steel Joist

K Joist

KCS Joist

LH Joist

DLH Joist

SLH Joist

Joist Girder

Wood Products

Beams

APA PRI

405

Anthony Wood

Boise Cascade

Georgia

Pacific

I Level

International Beams

Louisiana

Pacific

Nordic

Pacific Wood

RedBuilt

Roseburg Forest

Products

Standard Structures

You may edit these lists or create additional custom lists of your own. For more information on these redesign lists, includi

file format, editing procedure, and user d

efined lists refer to

Appendix A

Redesign Lists

Design Rules

–

Size / U.C.

The

Design Rules Spreadsheet

records the limitations for the design and may be accessed by selec

ting

Design Rules

on the

Spreadsheets Menu

You may create and name any number of design rules and assign different rules to various members.

Design Optimization

RISA

2D v10

The spread

sheet has

five

tabs:

Size / UC,

Concrete Rebar Masonry Wall, Wood Wall (Studs), and Wood Wall

(Fasteners).

The entries for the

Size / UC

tab are explained below:

Design Rule Labels

You must assign a unique label to the design rules.

You then

refer to the design rule by its label when assigning it to

members. The label column is displayed on all tabs of the spreadsheet.

Max/Min Depth

You may enforce depth restrictions by setting either a maximum and/or minimum depth.

Max/Min Width

You may enfor

ce width restrictions by setting either a maximum and/or minimum width.

Max Bending and Shear Check

Enter the maximum bending and shear unity checks. This should usually be specified as "1". If you desire a larger factor of

safety, provide a lower factor (

i.e. ".95").

Note



These entries are not currently used for

Wall Panel

design.

Design Rules

–

Concrete Rebar

The entries for the

Concrete Rebar

tab

are explained below.

Design Optimization

General Reference Manual

Note



If you would like to define specific flexural and shear rebar layouts for beams and columns, see

Rebar Layout

Database

Flexural Bars

Use the

Min Flex Bar

and

Max Flex Bar

columns to restrict bar sizes

for your flexural reinforcing.

Currently we support the

ASTM A615 (imperial), ASTM A615M ("hard" metric, i.e. #8M is an 8mm bar), BS 4449 (British), prENV 10080 (Euro),

CSA G30.18 (Canadian), and IS 1786 (Indian) reinforcement standards.

You may specify y

our rebar set in the

Global

Parameters

Concrete

You can force the program to analyze one bar size by setting the Min and Max values to be the same

bar.

Specify the yield strength of your flexural reinforcement in the

Flex St

eel

column.

Shear Ties

Use the

Shear Bar

column to enter the size of your shear ties.

Currently we support the ASTM A615 (imperial), ASTM

A615M ("hard" metric, i.e. #8M is an 8mm bar), BS 4449 (British), prENV 10080 (Euro), CSA G30.18 (Canadian), and IS

1786 (Indian) reinforcement standards. You may specify your rebar set in the

Global Parameters

Concrete

Specify the yield strength of your shear reinforcement in the

Shear Steel

column.

Legs per Stirrup

Use the

Legs per Sti

rrup

column to enter the specific information about how may legs (1 to 6) each of your shear ties is

expected to have.

Concrete

Cover

The last three columns are used to specify the clear cover measured to the shear rein

forcing. Note that the Top Cover is used

for all sides of Column members.

Design Rules

Masonry Walls

The entries for the

Masonry Wall

tab are explained below.

Block Nominal Height

This is currently not used in the program. This value will be used to make optimizing lintels easier by incrementing

the depth.

Design Optimization

RISA

2D v10

Block Nominal Width

This is used to calculate thickness of masonry walls. We use this value along with the value of grout / bar spacing to

determine the effective thickness of the wall. The effective thickness is based on table B3 of the Reinfo

rced Masonry

Block Nominal Length

This value is used to optimize the boundary zone length of the masonry walls. It is assumed that there are 2 cells per block

(typical for concrete masonry) and based on the

value of “bars per cell” we can increment the value of the boundary zone

while incrementing the number of bars in the boundary zone.

Flexural/Shear Steel Strength

Allows you to modify the yield strength of both the flexural and the shear reinforcement.

lf Weight

Clicking within the self weight column of the Design Rules spreadsheet shows you an expand dialog button. Clicking this

dialog button gives you two options:

.The first button will take the density input in the Materials spreadsheet and multiply that by the cross

sectional area of

the wall, defined here, to give the self

weight. This will display 'Material' in the Self Weight tab of the Design Rules

preadsheet.



The second button will use block material and grout weight, combined with the grout spacing and the width of the

block, to give the self

weight. This will display 'Custom' in the Self Weight tab of the Design Rules spreadsheet.

Design Rules

-Wood Wall (Studs)

Top Plate

Use the Top P

late column to specify the member to be used as a top plate for your wall. A top plate is a member that runs

continuously along the top of the wall studs. Note that you can use multiple plies of nominal lumber, or custom shapes.

Design Optimization

General Reference Manual

Sill Plate

Use the

Sill Pla

column to specify the member to be used as a sill plate for your wall. A sill plate is a member that runs

continuously along the bottom of the wall studs. Note that you can use multiple plies of nominal lumber, or custom shapes.

Studs

Use the Studs colu

mn to specify the member to be used for studs in your wall. Studs are vertical members in the wall,

attached to the sill plate at the bottom and the top plate at the top. Note that you can use multiple plies of nominal lumber

, or

custom shapes.

Min Stud Sp

ace

You may specify a minimum spacing of wall studs. The preset spacings are set at industry standards. Note that this value may

not be larger than the Max Stud Spacing.

Max Stud Space

You may specify a minimum spacing of wall studs. The preset spacings ar

e set at industry standards. Note that this value may

not be smaller than the Min Stud Spacing.

Note:



If you specify the maximum and minimum stud spacing as the same value, then we will use that value exclusively.

Green Lumber

Check this box if your moistu

re content is greater than 19%. The program will then multiply the Ga value of the shear panel

by 0.5 per Note 5 of Tables 4.3A and 4.3B of the NDS 2005 SDPWS.

Design Rules

Wood Wall (Fasteners)

Schedule

You can select the Code, and Panel Group you would like to use for design optimization.

By unchecking the

Select Entire

Panel Group

box an individual panel type may be assigned. For more information on this schedule, as well as information

on how to edit or create your own custom schedule, see

Appendix F

Wood De

sign Databases

Min/Max Panel Thick

These values set minimums and maximums for the thickness of the sheathing that will be designed. If the same value is input

for both max and min, then that will be the thickness used.

Double Sided

You can choose whether

you want the program to force sheathing on only one side of the panel, both sides, or to choose the

optimum based on weight.

Design Optimization

RISA

2D v10

Max/Min Nail Spacing

These values set minimums and maximums for the spacing of the nails that fasten the sheathing to the boundary

members

(top plate, sill plate, hold down chords). Note that a 12"

spacing is assumed for all field nailing (nails fastening the sheathing

to the internal studs).

HD Chords

You can choose what member size you would like to use for the Hold Down Chords (Pos

ts) at both ends of the wall panel.

Chord Material

You can specify whether the hold down chords are of the same material as the wall, or another material.

Hold Down Schedule

You can select the Code, and Hold Down Series you would like to use for design

optimization. By unchecking the

Use

Entire Series

box you my select an individual hold down product to be assigned. For more information on this schedule, as

well as information on how to edit or create your own custom schedule, see

Appendix F

Wood Design Databases

Optimization Procedure

Members

Member optimization is performed both on explicitly defined members and on members defined through the use of Section

Sets.

Members defined as part of a Section Set are checked to d

etermine which member has the highest code check value and

which member has the highest shear check value. These members are considered to be the controlling members for that

section set.

The controlling forces on a member or a section set are then applied

to new shapes satisfying the redesign parameters and a

code check is calculated. If the calculated code check and shear check falls within the specified range the shape is consider

to be an acceptable alternate.

Optimization Procedure

Walls

Wood Walls

For the optimization procedure on wood walls see

Wood Design

Masonry Walls

For the optimization procedure on masonry walls see

sonry Design.

Optimization Results

Suggested Shapes Spreadsheet

Access the

Suggested Shapes Spreadsheet

by selecting the

Results Menu

and then selecting

Members

Suggested

Shapes

Design Optimization

General Reference Manual

These are the suggested shapes resulting from the optimization calculations. They

are chosen from each member's assigned

Design List

. The suggested shape is

estimated

to most closely meet the criteria specified in the Design Rules without

exceeding them.

Note:



The suggested shape may be larger or smaller tha

n the current shape, except for the case of members brought over

from RISAFloor, for which the program never recommends downsizing.

To confirm that these alternate shapes are acceptable you

MUST

adopt any changes into the model then re

solve and check

the

results.

The suggested shapes are based on the forces for the current model.

Keep in mind that the current results are

based on the stiffness of the current shapes.

Changing the shapes will change the stiffness, which is why the model needs to

be resolved.

It may be necessary to cycle through this process a few times to achieve the best shapes.

You may try the new shapes by clicking the

Replace and Resolve

button

. The shapes listed in the

Suggested Shapes

column will only be used to update the model if the "Use Suggested?" box is checked for that particular member or section

set.

If the message "No Shapes Found" is given, then no satisfactory shapes could be found

in the Design List specified for that

member or section set.

This can occur for a number of reasons. Common reasons are:



The loads applied are too large for the shapes in the redesign list.



No load combinations were checked for the design of this material

type.

See

Load Combinations

Design Tab

for more information.



A code check could not be performed for a member in the section set.

See the Design Results or the

Warning Log

for these members.



The

member has not been assigned an initial redesign list. Check the Members and Section Sets spreadsheets to

be sure they are defined with a redesign list.



On-line shapes (RE, PI and BAR) cannot be redesigned.



If you've entered a minimum code check value and

the members assigned to this section set are lightly loaded, it

is possible that no shape generates a code check value high enough to exceed the minimum.



A code was not specified for that material on

Global Parameters

Codes

Drift78RISA

2D v10

Drift

You may calculate and report inter

story drift based on calculated joint displacements

in the X

direction

Simply specify

which joints represent which stories.

Once the solution is performed you may view the drift results in the

Stor

y Drift

spreadsheet.

To Define a Story for Drift Calculation



On the Boundary spreadsheet specify a joint label and, for the translational boundary condition for the desired

direction, enter

Story nn

, where nn is the story number.

Note



If a story 0 is NOT defined, the base height and displacement values are assumed to be zero (0.).



If a story is skipped (not defined), then there will be no calculations for both that story and

the following story.

Drift Results

Access the

Story Drift

spreadsheet by selecting it from the

Results

Menu.

This report lists the drift for all defined stories.

To calculate inter

story drift for a particular direction, the previous story displacement is subtracted from the current story

displacement.

For example, to calculate X direction drift for story 2, the X displacement for the joint

representing story 1 is

subtracted from the X displacement for the joint representing story 2.

As for story heights the vertical axis

is used to determine the distance.

For example, the story joint Y coordinate values are

used to calculate heights for X d

irection drift.

If you wish, you may define a "STORY 0" joint.

If defined, this story 0 joint's displacement and coordinate values will be

used for the story 1 calculations.

No drift calculations will be performed for story 0.

If a story 0 is NOT define

d, the base

height and displacement values are assumed to be zero (0.).

In this case, the coordinate value for the story 1 joint is used as

the story 1 height, and the displacement is used as the story drift.

If a story is skipped (not defined), then ther

e will be no calculations for both that story and the following story.

For example,

say we define stories 1, 2, 4, 5 and 6.

We don't define a story 3 joint.

When we view the drift report, there will be no results

for story 3, and there also will be no r

esults for story 4, since story 4 depends on the story 3 values.

DXF Files

General Reference Manual

DXF Files

You may read and writeexport DXF files.

Generally, you would read in a DXF file to create the geometry for a new structural

model, or you cou

ld write out a DXF file from an existing model to form the basis for a model or a CAD drawing.

This

feature provides two

way compatibility with any other program that can read and write DXF files.

This includes most major

CAD programs and many analysis p

rograms.

Note



Perform a Model Merge on any model created from a DXF file.

See

Model Merge

for more information.



You may want to round off the joint coordinates after importing a DXF file.

You may do this from the Tools

nu.When importing a DXF file it is essential to specify a column layer.

Only beams that are fully supported will be

imported.

Importing DXF Files

You may translate POINT’s, LINE elements and 3DFACE’s.

POINT’s are converted into joints, LINE’s are conver

ted into

members and 3DFACE’s are converted into plates.

Circles, arcs, polylines, text, etc. may be present in the DXF file, but

these will be ignored.

At this time, only the basic geometry will be translated via DXF files.

You have several options

ava

ilable for controlling how DXF files are imported.

They are as follows:

DXF Units

Select the units you used in the CAD model from which you produced the DXF fi

le.

The supported DXF units are none,

inches, feet, mm, cm, and meters.

CAD Scale

Enter the scale factor that will cause the DXF file to be scaled up or down to full scale.

For instance, if you had created a

scaled model in AutoCAD at a scale of 1/4"=12"

, then the appropriate scale factor to produce a full size RISA

2D model

would be 48.

The default is 1.0.

DXF Files

RISA

2D v10

DXF File Vertical Axis

Although it is not specifically noted in the AutoCAD documentation, the implied default vertical axis

is the positive Z

axisofthe current User Coordinate System.

The default vertical axis in RISA is usually the positive Y

axis and may be specified on the

Global Parameters

When you

import your model from a DXF file, you can have the program automatically rotate your geometry

so that the Y axis is now

the vertical axis for your RISA model.

Translate Layer Names to Section Sets

This is a Yes/No check box.

If you check the box “Yes”, the program will translate the DXF file's layer names into RISA

Section Sets Labels.

The progra

m requires that you add a prefix to each Layer Name to designate what type of material that

section set is defined for.

The prefixes are as follows:

Material Type

Layer Prefix

Cold Formed Steel

CF_

Concrete

CN_

Hot Rolled Steel

HR_

General Materials

GN_Wood

WD_

For example, let’s say you have designed a structure with Hot Rolled steel section sets that you want to call "Column"and "

Girder", as well as a Wood section set called "Joist". If you do not prefix your section sets then they will all be

imported as

General Material section sets.

To have them imported into the proper Material type the column layer would have to be

named "HR_Column", the girder a layer "HR_Girder", and the joists layer "WD_Joist".

Translate Shapes to Layer Names

This is a

Yes/No choice.

If you choose “Yes”, the program will take members and assign them to a shape based on their

shape label.

If there is not a database shape that corresponds to the DXF Layer Name, then these member will be assigned a

general RE4x4 shape or

a BAR2.

ote



hen assigning layer names in AutoCAD, remember to use an underscore character ("_") in place of a period

(".") where a period would normally occur.

For instance a C10X15.3 should be entered as C10X15_3.

RISA

-2Dwill automatically convert th

e “_” to a “.” when the DXF file is read in.

Exporting DXF Files

Only the joint, member, and element geometry will be translated and used to create an ASCII DXF file.

Any other

information such as the boundary conditions, loads, member end releases, etc.

will not be translated at this time.

You have

several options available for controlling how DXF files are exported as follows:

DXF Files

General Reference Manual

Joint Layer

Type the name of the

layer

for the joint point entities.

If you don’t enter anything, the default layer name will be “MODEL”.

Member Layer

Type the name of the layer

for the line entities.

If you don’t enter anything, the default layer name will be “MODEL”.

Note

that this

entry will be ignored if you select the option below to translate section set database shape names into layer names.

Plate Layer

Type the name of the layer

for the plate elements, which will be represented as 3DFACE entities.

If you don’t enter

anything,

the default layer name will be “MODEL”.

DXF Units

Select the units you desire the CAD model to be created in.

The options for the DXF units are none, inches, feet, mm, cm,

and meters.

CAD Scale

Enter the scale factor that will cause the full scale RISA mo

del to be scaled up or down to the desired drawing scale.

For

example, if you created a full scale model that you wanted scaled down to 1/4"=12", the factor would be 0.020833, which is

(.25/12).

Line End

Standoff Distance

Enter the distance you wish to h

ave the line entities “stand off” from the joints to which they are attached.

The standoff

distance is measured along the axis of the line.

The distance will be in the DXF units, which is defined below.

The distance

will be used as entered and will not

be scaled by the CAD Scale factor.

Note that if you create a DXF file with a non

zero standoff distance, it will be difficult to use the file for model geometry if

you read the file back into RISA.

(If you read such a file back in, you will end up with mu

ltiple joints at each member

endpoint which will separated by the standoff distance)

DXF Files

RISA

2D v10

DXF File Vertical Axis

Although it is not specifically noted in the AutoCAD documentation, the implied default vertical axis

is the positive Z

axisofthe current User Coordinate System.

The default vertical axis in RISA is usually the positive Y

axis and may be specified on the

Global Parameters

When you

export your model to a DXF file, you can have the program automatically rotate your geometry to

match the vertical axis of

your CAD program.

Translate Section Sets to Layer Names

This is a Yes/No check box.

If you check the box “Yes”, the program will translate Section Set Labels to layer names.

Layers will be created in the DXF file corresponding

to the section set

labels in the RISA model.

A “Yes” choice here

overrides any layer

name entered for the member layer.

The program will add a prefix to each section set layer to designate what type of material that section is.

The prefixes are as

foll

ows:

Material Type

Layer Prefix

Cold Formed Steel

CF_

Concrete

CN_

Hot Rolled Steel

HR_

General Materials

GN_

Wood

WD_

For example, let’s say you have designed a structure with Hot Rolled steel section sets called "Column"and " Girder", as well

a Wood section set called "Joist". If you type in a member layer name such as "STEEL" then all members, regardless of

size, will appear on a layer named "STEEL".

However, if you choose “Yes” for the

translate section sets to layers

option,

then all the me

mber that are assigned to the Column section set will appear on a layer named "HR_Column", the girders on a

layer named "HR_Girder", and the joists on a layer called "WD_Joist".

Translate Shapes to Layer Names

This is a Yes/No choice.

If you choose “Yes”,

the program will take members and assign them to a layer which uses their

shape label as the layer name.

Layers will be created in the DXF file corresponding to the shape

labels in the RISA model.

A “Yes” choice here overrides any layer

name entered f

or the member layer.

ote



If you check BOTH the

Translate Section Sets

and

Translate Shapes

boxes, then only the explicitly defined

shapes will be put placed on a layers according to their shape labels.

All members defined with section sets will

still be

placed on layers according to their section set label.



Please note that if the section set database shape designation includes one or more decimal point (".") characters,

the export will translate each occurrence of a decimal point character into an unde

rscore (“_”) character.

For

instance, a section set or shape label such as a C10X15.3 will translate into a layer name of

"C10X15_3" or

"HR_C10X15_3".



The DXF format does not properly recognize certain ASCII text characters for layer names (< > /

“ : ;

? * | = ‘).

Therefore, these characters should be avoided for shape or section sets when using the "translate to layer names"

options.

Merge After Importing a DXF File

It's always a good idea to do a Model Merge on any model created from a DXF file!

the process of creating a wire frame

model in your CAD software, certain events may take place that cause end

points of LINE elements that were once matched

to become mismatched by very small amounts.

This most often happens as a result the following:

DXF Files

General Reference Manual



Use

of mirroring or rotating operations.



Improper use or lack of use of point snaps.



Trimming or breaking operations.



Inconsistent precision when inputting point coordinates from the keyboard.

Model Merge combines joints that are within the “merge tolerance”

distance of one another.

The default distance for the

merge tolerance is 0.01 ft. for all unit types.

You can also deal with several other possible problems by performing a

Model Merge

This feature will also deal with

intermediate joints along member spa

ns, a common problem in models created from DXF drawings and members that cross,

but do not have

joints

at their intersection point.

See

Model Merge

for more information.

DXF Element Numbers

Different CAD packages handle o

rdering of geometric data in their DXF files in two basic ways.

Method 1:

Entities are written out into the DXF file based on the order in which they were created within the CAD program itself

regardless of the order in which they were selected at the time

the DXF file was made.

Different operations such as copying,

mirroring, arraying, etc. can produce unexpected results and it therefore becomes necessary to consult your CAD program

documentation to understand how it stores and orders the geometry that yo

u create via these various operations.

Method 2:

Entities are written out into the DXF file based on the order in which they were selected at the time the DXF file was made.

AutoCAD is such a program.

In order to control the ordering of the LINE entities

, you must select the "Entities" option

under the DXFOUT command and then select the lines in the order that you want them to appear in the RISA model.

Note



Another option to help improve the ordering of the joints, members and elements in a model obtained

from

reading in a DXF file is to sort

and relabel

them once in RISA.

DXF File Format

The specific DXF file that you may read and write is the ASCII Drawing eXchange Files (DXF) file.

Please note that

AutoCAD has several different forms of DXF files avail

able.

ASCII is the default form

and is the only form currently

supported

The DXF read/write feature was written based on the DXF documentation for AutoCAD release 14.

The feature

has been tested with AutoCAD Versions 13 and 14.

The following is a short

excerpt of the AutoCAD ASCII DXF format.

This information is provided to help you debug any

problems you may be having with DXF files that you are trying to read.

For more complete information, consult your CAD

documentation.

General

A DXF file is compo

sed of sections of data.

Each section of data is composed of records.

Each record is stored on it’s own

line.

Each particular item is stored as two records, the first record is a group code and the second record is the data or a

keyword.

RISA only read

s the ENTITIES section.

Group Codes

Each 2 record item start with an integer group code.

RISA recognizes the following group codes:

Group Code

Description

DXF Files

RISA

2D v10

Identifies the following overall

keywords: SECTION, ENDSEC, and

EOF.

Within the ENTITIES section

also identifies POINT, LINE, and

3DFACE

.2Identifies a section name (I.e.,

ENTITIES)

Identifies a layer

name.

10, 11, 12, 13

Identifies the X coordinate of the 1st,

2nd, 3rd and 4th points of an item.

20, 21, 22, 23

Identifies the Y coordinate o

f the 1st,

2nd, 3rd and 4th points of an item.

30, 31, 32, 33

Identifies the Z coordinate of the 1st,

2nd, 3rd and 4th points of an item.

First and Last Records for a DXF file

Each DXF file must start with the first record as the group code “0”.

The 2nd

record must be the keyword “SECTION”.

Each DXF file must have the 2nd to last record as the group code “0".

The last record must be the keyword

“EOF”.

Entities Section

The ENTITIES section will be identified by a group code of “0”, followed in the next

record by the keyword “SECTION”.

The next record will be the group code 2, followed in the next record by the keyword “ENTITIES”.

Item Formats within the ENTITIES Section

The POINT format is started by a group code of “0” followed by the keyword “POINT”.

The layer

name for the POINT will

start with a group code record of 8, followed by a record with the actual layer name.

The coordinates for the point will be started by the 10, 20, and 30 group codes respectively for the X, Y, and Z coordinates.

Other g

roup codes and data may be present within the POINT data but these will be ignored.

The LINE format is started by a group code of “0” followed by the keyword “LINE”.

The layer name for the LINE will start

with a group code record of 8, followed by a recor

d with the actual layer name.

The coordinates for the first point will be started by the 10, 20, and 30 group codes respectively for the X, Y, and Z

coordinates. The coordinates for the second point will be started by the 11, 21, and 31 group codes respect

ively for the X, Y,

and Z coordinates.

Other group codes and data may be present within the LINE data but these will be ignored by RISA

2D.

The 3DFACE format is started by a group code of “0” followed by the keyword “3DFACE”.

The layer name for the

3DFAC

E will start with a group code record of 8, followed by a record with the actual layer name.

The X, Y, and Z coordinates for the 1st through 4th points will be started by the 10, 20, and 30 through 14, 24, and 34 group

codes respectively.

Other group code

s and data may be present within the 3DFACE data but these will be ignored.

AutoCAD Layer Names

The only valid characters in an AutoCAD layer

name are the letters A to Z, the numbers 0 to 9, and the three following

characters: the dollar sign “$”, the un

derscore “_”, and the dash “

-”.Dynamic Analysis

Eigensolution

General Reference Manual

Dynamic Analysis

Eigensolution

The dynamic analysis calculates the modes and frequencies

of vibration for the model. This is a prerequisite to the response

spectra analysis,

which uses these frequencies to calculate forces, stresses and deflections in the model. For more

information, see

"Dynamic Analysis

Response Spectra"

You may calculate up to 500 modes for a model.

The process used to calculate the modes is called an e

igensolution.

The

frequencies and mode shapes

are referred to as eigenvalues and eigenvectors.

The dynamic analysis uses a lumped mass matrix with inertial terms.

Any vertical loads that exist in the

Load Combination

for Mass

will be automatically conver

ted to masses based on the acceleration of gravity entry on the Solution tab of the

Global Parameters. However, you must always enter the

inertial

terms as Joint Masses.

To Perform a Dynamic Analysis / Eigensolution

You may wish to solve a static analysis first to verify that there are no instabilities.

Click

Solve

on the main menu and select

Dynamics

from the solution options.

Spec

ify the load combination to use as the mass

and the number of modes to solve.

Note



You may view the mode shapes

graphically by choosing this option in the Plot Options.



Refer to

"Dynamic Analysis

Response Spectra"

for more information on that type of dyn

amic analysis.



The

Accelerated Solver

is the recommended solution choice as it will converge significantly faster than the

standard solver.

The

Standard Solver

is included to allow users proven and accepted results for comparison

purposes.

Required Numb

er of Modes

You may specify how many of the model’s modes (and frequencies) are to be calculated.

The typical requirement

is that

when you perform

the response spectra analysis

(RSA), at least 90% of the model's mass

must participate in the solution.

Mass participation

is discussed in the Response Spectra Analysis section.

Dynamic Analysis

Eigensolution

RISA

2D v10

The catch is you first have to do a dynamic analysis in order to know how muc

h mass

is participating so this becomes a trial

and error process.

First pick an arbitrary number of modes (5 to 10 is usually a good starting point) and solve the RSA.

you have less than 90% mass, you'll need to increase the number of modes and try a

gain.

Keep in mind that the more modes

you request, the longer the dynamic solution will take.

Note



If you are obtaining many modes with little or no mass

they are probably local modes.

Rather than asking for

even more modes and increasing the solution t

ime see

"Dynamics Troubleshooting

–

Local Modes"

to learn how

to treat the unwanted modes.

Dynamic Mass

The eigensolution

is based on the stiffness characteristics of your model and also on the mass

distribution in your model.

There must be mass assigned to be able to perform the dynamic analysis.

Mass may be calculated automatically from your

loads or defined directly.

In order to calculate the amount and location of the mass contained in your mode

l, RISA takes the vertical loads contained in

the load combination you specify for mass and converts them using the acceleration of gravity defined in the

Global

Parameters

The masses are lumped at the joints and applied in

oth

global directions (X

and

, Y ).

You may also specify mass directly.

This option allows you to restrict the mass to a direction.

You can also apply a mass

moment of inertia to account for the rotational inertia effects for distributed masses.

See

"Loads-

Joint Load / Displacement"

to learn more about this.

Note



Only the VERTICAL loads (including vertical components of inclined loads) contained in the load combination

are converted to mass!



The self

weight of the model is NOT automatically included in

the mass

calculation.

If you wish to have self

weight included, you must have it defined as part of the load combination.

Solution Method

You may choose between the Standard Solver and the Accelerated Solver.

The accelerated solver uses an accelerated su

b-space iteration with a Lanzcos starting vector.

The accelerated solver is the default and should produce solution in a fraction

of the time that the standard solver would take to produce them. The Standard Solver uses a simple sub

space iteration to

sol

ve for the natural frequencies.

This solver has been used for years and the accuracy of the results is very well established.

It has been included only for comparative / verification purposes.

Eigensolution Convergence

The eigensolution procedure for dynamic analysis is iterative, i.e. a guess is made at the answer and then improved upon unti

the guess from one iteration

closely matches

the guess from the previous iteration.

The tolerance value is specified in the

"Global Parameters"

and indicates how close a guess needs to be to consider the solution to be converged.

The default value

of .001 means the frequencies

from the previous cyc

le have to be within .001 Hz of the next guess frequencies for the

solution to be converged.

You should not have to change this value unless you require a more accurate solution (more

accurate than .001?).

Also, if you're doing a preliminary analysis, yo

u may wish to relax this tolerance to speed up the

eigensolution.

If you get warning 2019 (missed frequencies) try using a more stringent convergence tolerance

(increase the

exponent value for the tolerance).

Saving Dynamic Solutions

After you’ve done the dynamic solution, you can save

that solution to file to be recalled and used later.

Note

Dynamic Analysis

Eigensolution

General Reference Manual

87This solution is saved in a .__

file and will be deleted when the Save or Save As options are used to overwrite

the file.

You may

also delete this file yourself.

Work Vectors

When you request a certain number of modes for dynamic analysis (let's call that number N), RISA tries to solve for just a

ew extra modes.

Once the solution is complete, RISA goes back to check that the modes it solved for are indeed the N

lowest modes.

If they aren't, one or more modes were missed and an error is reported.

Dynamics Modeling Tips

Dynamics modeling

can be quite a bit different than static modeling.

A static analysis will almost always give you some sort

of solution, whereas you are not guaranteed that a dynami

cs analysis will converge to a solution.

This is due in part to the

iterative nature of the dynamics solution method, as well as the fact that dynamics solutions are far less forgiving of model

ing

sloppiness than are static solutions.

In particular, the

way you model your loads for a static analysis can be very different

than the way you model your mass

for a dynamic analysis.

The term “dynamics solution” is used to mean the solution of the free vibration problem of a structure, where we hope to

obtain f

requencies

and mode shapes

as the results.

In general, the trick to a “good” dynamics solution is to model the structure stiffness and mass

with “enough” accuracy to get

good overall results, but not to include so much detail that it take hours of computer

run time and pages of extra output to get

those results.

Frame problems are simpler to model than those that include plate elements.

“Building type” problems, where

the mass is considered lumped at the stories are much easier to successfully model than

say a cylindrical water tank with

distributed mass.

It is often helpful to define a load combination just for your dynamic mass case, separate from your “Dead

Load” static case (You can call it “Seismic Mass”).

Your seismic mass load combination will oft

en be modeled very

differently from your “Dead Load” static case.

If you apply your dynamic mass

with distributed loads

or surface loads

on members/plates that are adjacent to supports,

remember that the some of the load will go directly into the support a

nd be lost to the dynamic solution.

The mass that can

actually vibrate freely is your “active mass”, as opposed to your “static mass” which includes the mass lost into the support

If you are having trouble getting 90% mass participation, you should rou

ghly calculate the amount of mass that is being lost

into your supports.

You may need to reapply some of your mass as joint loads to your free joints.

Or you may want to add

more free joints to your model, by splitting up your plates or beams.

Modes for

discretized mass

models with very few degrees of freedom may not be found by the solver, even if you know you

are asking for fewer modes than actually exist.

In this case it may be helpful to include the self weight

of the model with a

very small factor (

i.e. 0.001) to help the solver identify the modes.

Distributed mass

models with plate elements, like water tanks, often require special consideration.

You will want to use a

fine enough mesh

of finite elements

to get g

ood stiffness results.

Often though, the mesh required to obtain an accurate

stiffness will be too dense to simply model the mass with self

weight or surface loads.

You will want to calculate the water

weight and tank self

weight and apply it in a more d

iscrete pattern than you would get using surface loads or self

weight.

This method of using fewer joints to model the mass than to model the stiffness is often referred to as "discretizing" the

mass.

You want to lump the mass at fewer points to help the

solution converge faster, however you have to be careful to still

capture the essence of the dynamic behavior of the structure.

Whenever you perform a dynamic analysis of a shear wall

structure, and the walls are connected to a floor, you must be

careful t

o use a fine mesh

of finite elements for each wall.

Each wall should be at least 4 elements high between floors.

This

will give you at least 3 free joints between them.

When you perform a dynamic analysis of beam structures, such that

you are trying to capture the flexural vibrations, (i.e., the

beams are vibrating vertically or in the transverse direction), you must make sure that you have at least 3 free joints along

the

member between the points of support.

If you use a distributed

load as the mass, you must remember that some of the load

will automatically go into the supports and be “lost” to the dynamic solution.

In general, you will get the best results by

applying your mass as joint loads to the free joints.

Dynamic Analysis

Eigensolution

RISA

2D v10

Modal Frequency Res

ults

Access the

Modal Frequency

spreadsheet by selecting it from the

Results

Menu.

These are the calculated model frequencies and periods.

The period is simply the reciprocal of the frequency.

These values

will be used along with the mode shapes

when a response spectra analysis

is performed.

The fir

st frequency is sometimes

referred to as the model's natural or fundamental frequency.

These frequency values, as well as the mode shapes, will be

saved and remain valid unless you change the model data, at which time they will be cleared and you need to

re-solve the

dynamics to get them back.

Also listed on this spreadsheet are the participation factors

for each mode for each global direction, along with the total

participation.

If no participation factors are listed, the response spectra analysis

(RSA)

has not been performed for that

direction.

If the RSA has been done but a particular mode has no participation factor listed, that mode shape is not

participating in that direction.

This usually is because the mode shape represents movement in a directio

n orthogonal to the

direction of application of the spectra.

See

"Dynamic Analysis

Response Spectra"

for more information.

Mode Shape Results

Access the

Mode Shape

spreadsheet by selecting it from the

Results

Menu.

These are the model's mode shapes.

Mode shapes have no units and represent only the movement of the joints relative to

each other.

The mode shape values can be multi

plied or divided by any value and still be valid, so long as they retain their

value relative to each other.

To view higher or lower modes you may select them from the drop

down list of modes on the

Window Toolbar.

Note

Dynamic Analysis

Eigensolution

General Reference Manual

89Keep in mind that these mode shapes

do not, in and of themselves, represent model deflections.

They only

represent how the joints move relative to each other.

You could multiply all the values in any mode shape by any

constant value and that mode shape would still be valid.

Thus, no unit

s are listed for these mode shape values.

These mode shapes

are used with the frequencies

to perform a Response Spectra Analysis.

The first mode is sometimes

referred to as the natural or fundamental mode of the model.

The frequency and mode shape values

will be saved until you

change your model data.

When the model is modified, these results are cleared and you will need to re

solve the model to get

them back.

You can plot and animate the mode shape of the model by using the Plot Options.

This allows you to verify the mode

shapes

that were obtained and highlights local modes

making them easy to troubleshoot.

See

"Graphic Display"

for more

informati

on.

Dynamics Troubleshooting

–

Local Modes

A common problem

you may encounter are “localized modes”.

These are modes where only a small part of the model is

vibrating and the rest of the model is not.

Localized modes are not immediately obvious from looking at the frequency

numeric mode shape results, but they can be spotted pretty easily using the mode shape animation

feature.

Just plot the mode

shape and animate it. If only a small part of the model is moving, this is probably a localized mode.

The problem with localized

modes is that they can make it difficult to get enough mass

participation

in the response spectra

analysis

(RSA), since these local modes don’t usually have much mass associated with them.

This will show up if you do an

RSA with a substantial number of mo

des but get very little or no mass participation. This would indicate that the modes

being used in the RSA are localized modes.

Quite often, localized modes are due to modeling errors (erroneous boundary conditions, members not attached to plates

correctly

, etc.).

If you have localized modes in your model, always try a Model Merge before you do anything else.

See

"Model Merge"

for more information.

Dynamic Analysis

Response Spectra

RISA

2D v10

Dynamic Analysis

Response Spectra

A response spectra analysis may be performed after the dynamic analysis to obtain forces, stresses and deflections.

general, the response spectra analysis procedure is based on the assumption that the dynamic response of a structura

l model

can be approximated as a summation of the responses of the independent dynamic modes of the model.

To Perform a Response Sp

ectra Analysis

Select

Dynamics (Eigensolution / Response Spectra)

from the

Solve

menu.

Set the Eigensolution parameters.

For help on an item, click

and then click the item.

Select the desired

Combination Method

Then use the checkboxes to indicate which directions you want to perform

your response spectra analysis.

Select the spectra to be used for each direction.

Then specify the other paramete

rs.

For help on an item, click

and then click the item.

Note



For a more thorough explanation of the Eigensolution options refer to

Dynamic Analysis

Eigensolution

.Upon the completion of the solution you are returned to the

Frequencies

and

Participation

spreadsheet and the

participation yielded by the RSA is listed.

To view model results such as forces/deflections/re

actions you will

need to create a load combination on the

Load Combination

spreadsheet that includes the spectra results.

See

below.

To Include Response Spectra Analysis Results in a Load Combination

After running the response spectra analysis go to the d

esired combination on the

Load Combination

spreadsheet.

In the

BLC

column enter "

"or"SY" as the BLC entry (

for the X direction RSA results,

for the Y direction

RSA results).

To scale the spectral results enter the spectra

scaling

factor in the

ctor

column.

Dynamic Analysis

Response Spectra

General Reference Manual

Note



You can include more than one spectra solution in a single load combination.

If you do this you can also have

RISA

2D combine the multiple RSA results using an SRSS summation.

To do this, set the "RSA SRSS" flag for

the combination to "

+" or “

-”.Use “+” if you want the summed RSA results (which will be all positive) added to

the other loads in the load combination.

Use “

” if you want the summed results subtracted.

Response Spectra

The response spectra

represent the maximum response of any single degree of freedom (SDOF) system to a dynamic base

excitation.

The usual application of this method is in seismi

c (earthquake) analysis.

Earthquake time history data is

converted into a "response spectrum".

With this response spectrum, it is possible to predict the maximum response for any

SDOF system.

By "any SDOF system", it is meant a SDOF system with any natu

ral frequency.

"Maximum response" means

the maximum deflections, and thus, the maximum stresses for the system.

Response Spectra Analysis Procedure

In the response spectra analysis procedure, each of the model's modes is consider

ed to be an independent SDOF system.

The

maximum responses for each mode are calculated independently.

These modal responses are then combined to obtain the

model's overall response to the applied spectra.

The response spectra method enjoys wide acceptan

ce as an accurate method for predicting the response of any structural

model to any arbitrary base excitation, particularly earthquakes.

Building codes require a dynamics based procedure for

some structures.

The response spectra method satisfies this dyn

amics requirement.

The response spectra method is easier,

faster and more accurate than the static procedure so there really isn't any reason to use the static procedure.

If you wish to learn more about this method, an excellent reference is

Structural Dy

namics, Theory and Computation

by Dr.

Mario Paz

(1991, Van Nostrand Reinhold).

Frequencies Outside the Spectra

If a response spectra analysis is solved using modal frequency

values that fall outside the range of the selected spectra, RISA

will extrapolate

to obtain spectral values for the out

-of-

bounds frequency.

If the modal frequency is below the smallest

defined spectral frequency, a spectral velocity will be used for the modal frequency that will result in a constant Spectra

Displacement from the smal

lest defined spectral frequency value.

A constant spectral displacement is used because modes in

the “low” frequency range will tend to converge to the maximum ground displacement.

If the modal frequency is above the

largest defined spectral frequency, a

spectral velocity will be used for the modal frequency that will result in a constant

Spectra Acceleration from the largest defined spectral frequency value.

A constant spectral acceleration

is used because

modes in the “high” frequency range tend to con

verge to the maximum ground acceleration (zero period acceleration).

Dynamic Analysis

Response Spectra

RISA

2D v10

Mass Participation

The mass participation factors reported on the

Frequencies Spreadsheet

reflect how much each mode participated in the

Response Spe

ctra Analysis solution.

Remember that the RSA involves calculating separately the response for each mode to

the applied base excitation represented by the spectra.

Here is where you can tell which modes are important in which

directions.

Higher particip

ation factors indicate more important modes.

The participation factor itself is the percent of the

model's total dynamic mass that is deflecting in the shape described by the particular mode.

Thus, the sum of all the

participation factors in a given dire

ction can not exceed 100%.

The amount of participation for the mode may also reflect how much the mode moves in the direction of the spectra

application.

For example, if the 1st mode represents movement in the global Y direction it won't participate much,

if at all, if

the spectra is applied in the global X direction.

You can isolate which modes are important in which directions by examining

the mass

participation.

Note



Usually for the RSA to be considered valid, the sum of the modal participation factors

must equal or exceed

90%

If you do an RSA and the total participation is less than 90%, you need to return to the dynamic solution

and redo the dynamic analysis with more modes.

If you are getting a lot of modes with little or no participation

see

Dynamics Troubleshooting

–

Local Modes



Models with a large amount of mass lost into boundary conditions may have difficulty achieving 90% mass

participation.

See

Dynamics Modeling

for more information.

Modal Combination Option

There are three choices for combining your modal results: CQC, SRSS, or Gupta.

In general you will want to use either CQC

or Gupta.

For models where you don’t expect much rigid response, yo

u should use CQC.

For models where the rigid

response could be important, you should use Gupta.

An example of one type of model where rigid response would be

important is the analysis of shear wall

structures.

The SRSS method is offered in case you need

to compare results with the

results from some older program that does not offer CQC or Gupta.

CQC stands for "Complete Quadratic Combination".

A complete discussion of this method will not be offered here, but if

you are interested, a

good reference on this method is

Recommended Lateral Force Requirements and Commentary, 1999

published by SEAOC (Structural Engineers Assoc. of Calif.).

In general, the CQC is a superior combination method because

it accounts for modal coupling quite wel

The

Gupta method is similar to the CQC method in that it also accounts for closely spaced modes.

In addition, this method

also accounts for modal response that has “rigid content”.

For structures with rigid elements, the modal res

ponses can have

both rigid and periodic content.

The rigid content from all modes is summed algebraically and then combined via an SRSS

combination with the periodic part which is combined with the CQC method.

The Gupta method is fully documented in the

reference,

Response Spectrum Method

, by Ajaya Kumar Gupta (Published by CRC Press, Inc., 1992).

The Gupta method defines lower ( f 1 ) and upper ( f 2 ) frequency

bounds for modes containing both periodic and rigid

content.

Modes that are below the lower

bound are assumed to be 100% periodic.

Modes that are above the upper bound are

assumed to be 100% rigid.

Risa technologies 2D User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual