FTA ADwin-Gold User's Reference Manual
Fracture Technology
Associates
Non-Linear Fracture Toughness Testing and Analysis
Version 3+.16.01
Users’ Reference Manual
January 2016
Keith Donald
Amy Blair
Fracture Technology Associates
2412 Emrick Boulevard
Bethlehem, PA 18020
610-868-3054
www.FractureTech.com
Page 2 of 148
NLFT Testing - Series 2015 - V3+.16.01
Table of Contents
1.0 The FTA NLFT Testing and Analysis System .............................................7
1.1 Introduction .................................................................................7
1.2 Software .....................................................................................7
1.2 The ADwin Gold .........................................................................7
1.4 Other Hardware Requirements ...................................................9
1.5 License Agreement.....................................................................9
1.6 Manual Layout ............................................................................9
2.0 Installation Guide ...................................................................................... 11
2.1 Hardware and Drivers ............................................................... 11
2.1.1 Analog input and output connections ............................. 11
2.1.2 Digital input and output connections .............................. 12
2.2 Connecting the FTA-DCPD Current Supply and Amplifier ........ 13
2.3 PC Setup and Installation of the FTA Software ........................ 15
2.4 Installing the ADWin Drivers on the PC .................................... 16
2.5 Testing in Simulation ................................................................ 18
2.5 Tuning ...................................................................................... 18
3.0 Using the NLFT Testing Software ............................................................. 19
3.1 Understanding Testing Files ..................................................... 19
3.2 Running a Test Using the FTA NLFT Software ........................ 20
3.2.1 Setup ............................................................................. 20
3.2.2 Running The Test .......................................................... 25
4.0 NLFT Testing Software: Description of Menus and Tabs ......................... 29
4.1 Splash Screen .......................................................................... 29
4.2 Main Menu ................................................................................ 30
4.3 File ............................................................................................ 30
4.3.1 Save Analysis File ......................................................... 30
4.3.2 Exit ................................................................................. 31
4.4 Config ....................................................................................... 31
4.4.1 Hardware Configuration ................................................. 32
4.4.1.1 Calibration (compliance) .................................. 32
4.4.1.2 Calibration (DCPD).......................................... 33
4.4.1.3 Configuration (Compliance and DCPD) ........... 34
4.4.2 Test Set-up .................................................................... 36
4.4.2.1 Initialize ........................................................... 37
4.4.2.2 Calibration ....................................................... 40
4.4.2.3 Coefficients ..................................................... 44
4.4.2.4 Dimensions ..................................................... 46
4.4.2.5 Compliance ..................................................... 48
4.4.2.6 DCPD .............................................................. 50
4.4.2.7 Storage ............................................................ 52
4.4.2.8 Limits ............................................................... 54
4.4.3 General information ....................................................... 55
4.4.3.1 General ........................................................... 56
4.4.3.2 Precrack .......................................................... 57
Page 3 of 148
NLFT Testing - Series 2015 - V3+.16.01
4.5 Control ...................................................................................... 58
4.5.1 Ramp Generator: Compliance and DCPD ..................... 58
4.6 Display ...................................................................................... 63
4.6.1 Status ............................................................................ 63
4.6.2 Load-Displacement ........................................................ 64
4.6.3 J – Delta a...................................................................... 66
4.7 Comments ................................................................................ 67
4.8 Help .......................................................................................... 67
5.0 Using the FTA Analysis Software ............................................................. 69
5.1 How the NLFT Analysis Program Works ................................ .. 69
5.2 Understanding the Files Used by the Analysis Program ........... 70
5.3 E1820 Analysis Procedure ....................................................... 71
5.4 E399 Analysis Procedure ......................................................... 74
6.0 NLFT Analysis Software: Description of Menus and Tabs ........................ 79
6.1 Splash Screen .......................................................................... 79
6.2 Main Form: Menu Items ............................................................ 79
6.2.1 File ................................................................................. 80
6.2.1.1 Open ............................................................... 81
6.2.1.2 Save ................................................................ 81
6.2.2 Display ........................................................................... 81
6.2.3 Help ............................................................................... 81
6.2.4 Quit ................................................................................ 81
6.3 Main Form: Tabs ...................................................................... 82
6.3.1 Control ........................................................................... 82
6.3.2 Coeff[icient]s .................................................................. 85
6.3.3 General .......................................................................... 86
6.3.4 Dimensions .................................................................... 88
6.3.5 Visuals, Etc. ..................................................................... 89
6.3.6 Comments ..................................................................... 91
6.3.7 Data ............................................................................... 92
6.3.8 Load-Disp Data .............................................................. 94
6.4 Processing The Data ................................................................ 96
6.4.1 Run Non-Linear Analysis ............................................... 96
6.4.2 Process Load-Disp Data ................................................ 96
6.5 Display ...................................................................................... 96
6.5.1 J – delta a Display ......................................................... 97
6.5.2 Output Display ............................................................... 98
6.5.3 Load-displacement Display ............................................ 99
6.6 Post Processing ..................................................................... 101
7.0 Analysis Utility ........................................................................................ 103
7.1. Non-Linear Report .................................................................. 103
7.1.1 User Input .................................................................... 105
7.1.2 Reduced Data .............................................................. 106
7.1.3 J-plot ............................................................................ 107
7.1.4 Cover page .................................................................. 108
7.1.5 Raw Data ..................................................................... 110
Page 4 of 148
NLFT Testing - Series 2015 - V3+.16.01
7.1.6 Additional Data ............................................................ 111
7.1.7 Variables ...................................................................... 112
7.2. Load-Disp and Linear Report ................................................. 113
7.2.1 Load Disp..................................................................... 114
7.2.2 Load Time .................................................................... 115
7.2.3 User Input .................................................................... 116
7.2.4 Cover Page .................................................................. 117
7.2.5 K-Plot ........................................................................... 118
7.2.6 K-Plot ........................................................................... 119
7.2.7 Reg Data...................................................................... 120
7.2.8 Variables ...................................................................... 121
8.0 The NLFT Testing PLAYBACK software ................................................ 123
8.1 Using the Testing Playback Software ..................................... 123
8.2 Description of Menus and Tabs .............................................. 124
8.2.1 Splash Screen ............................................................. 124
8.2.2 Main Menu ................................................................... 125
8.2.2.1 File ................................................................ 125
8.2.2.2 Open ............................................................. 126
8.2.2.3 Save Analysis File As .................................... 126
8.2.2.4 Save Metric Load-Displacement ................... 126
8.2.3 Input ............................................................................. 126
8.2.3.1 Data ............................................................... 127
8.2.3.1.1 Initialize ........................................ 127
8.2.3.1.2 Coefficients .................................. 128
8.2.3.1.3 Dimensions .................................. 129
8.2.3.1.4 Calibration ................................... 130
8.2.3.2 Options .......................................................... 131
8.2.4 Display ......................................................................... 132
8.2.4.1 Load-Displacement ....................................... 132
8.2.4.2 J – Delta a ..................................................... 133
8.2.5 Help ............................................................................. 133
Appendix A: Recovery from System Crash ................................................. 135
Appendix B: Descriptions of Analysis Files ................................................. 137
B1: Log file .................................................................................... 137
B1a: Compliance .................................................................. 137
B1b: Potential Drop .............................................................. 139
B2: Compliance .in5 file ................................................................ 141
B2a: Field Descriptors .......................................................... 142
B2b: Glossary of Variables ................................................... 142
B3: RAW file ................................................................................. 146
B4: UNL file ................................................................................... 147
Page 5 of 148
NLFT Testing - Series 2015 - V3+.16.01
Page 6 of 148
NLFT Testing - Series 2015 - V3+.16.01
1.0 The FTA NLFT Testing and Analysis System
1.1 Introduction
Fracture Technology Associates’ fourth-generation Non-Linear Fracture Toughness
(NLFT) system is an updated hardware and software package designed primarily for
non-linear fracture toughness testing and analysis (ASTM E1820, E1921), ), although
linear elastic testing and analysis is supported (ASTM E399). Each system consists of
an ADwin Gold signal processor and a computer running the FTA NLFT software.
Enhancements to the software include the ability to perform cyclic J and da/dt with a K
profile, desirable for accelerated environmentally assisted cracking tests (K
Two analysis packages are included with each system: 1) standard analysis and 2)
testing playback software, which allows the user to reprocess unloading slopes that may
have captured non-linear crack measurement data during testing.
FTA’s basic NLFT (ASTM E1820, E1921) testing application is designed to run with the
ADwin Gold and any closed loop servo-hydraulic mechanical test machine and
controller, suitably configured for non-linear fracture toughness testing. It is important to
note that the fourth-generation software requires an ADwin with an integrated USB port:
older Adwins are not supported.
Ieac
).
1.2 Software
The basic software application uses either compliance (NLFT-C) or DC potential drop
(NLFT-D) for non-linear fracture toughness testing with a single crack monitor. The
combined application (NLFT-C/D) includes either, independent or simultaneous
compliance unloading and DC potential drop monitor of crack size.
The FTA NLFT analysis program runs independently of the Adwin Gold and has been
upgraded as well. The analysis program can run analysis files created by the new
testing software as well as previous versions.
1.3 The ADwin Gold
The hardware component of FTA’s testing system is the ADwin-Gold signal processor,
manufactured by the German company Jäger. The ADwin takes over from the test
machine controller and performs all function generation, data acquisition, and real-time
data processing, using the ADbasic programming language. ADbasic controls both high
(such as command control and data acquisition) and low priority processes (such as
determination of crack length). The ADwin performs all tasks on a priority basis
regardless of the computer’s workload and time-critical processes run independently of
Page 7 of 148
NLFT Testing - Series 2015 - V3+.16.01
the PC operating system. Thus, if the computer running the FTA software crashes, the
ADwin continues to maintain control and collect data. When the computer is rebooted, it
can access the ADwin process and tests continue uninterrupted.
The ADwin has a dedicated Analog Devices SHARC DSP processor; local memory; and
high-speed 16-bit resolution analog input and output. It provides real-time response
within one microsecond. Further documentation can be found in the ADwin manuals
provided with FTA systems.
Page 8 of 148
NLFT Testing - Series 2015 - V3+.16.01
1.4 Other Hardware Requirements
Required hardware for the FTA testing package includes the ADwin Gold and a
computer running the FTA software. A computer (either 32-bit or 64-bit) with a Pentium
3 processor and 256M memory (or better) and a CD/DVD drive is recommended.
Windows versions 98 thru 7 are supported, although ADwin drivers will differ according
to the OS used (see section 2.4 of this manual for further details).
For potential drop methods of crack measurement, FTA supplies its own high-quality,
DC potential drop instrumentation (FTA-DCPD). The FTA-DCPD was specifically
designed for the precise current and amplifier stability necessary for the reversing DC
potential drop method of monitoring crack length and consists of two units: a
programmable linear DC power supply with built-in solid-state polarity-reversing relays
and a two channel precision differential DC amplifier
Please consult FTA for additional details regarding system requirements.
1.5 License Agreement
Familiarization with the background and theory of fracture toughness testing as well as
the American Society for Testing and Materials (ASTM) standards for fracture
toughness testing (E1820, E1921, E399) is strongly recommended. Fracture
Technology Associates (FTA) assumes no liability for inappropriate use of this software
and hardware system. It is the user’s responsibility to provide back-up verification of the
performance and accuracy of this software package (i.e., visual checking of crack
length, independent monitoring of the applied loads, and redundant checking of the
analysis).
Each test system requires a software license for each of the two required testing
applications. Permission is granted to make copies of the software for back-up
purposes. The analysis software does not require a license for multiple copies and may
be loaded on additional computers for convenience of use. All rights and title to the
application software shall remain the sole and exclusive property of FTA. Distribution of
this software to another party is prohibited.
1.6 Manual Layout
This manual is intended as a beginning reference for new users of the FTA testing and
analysis software. The following section describes setup and installation of the ADwin
Gold; FTA-DCPD current supply and amplifier; and FTA software. Section 3.2 provides
step-by-step instructions to guide new users through the running of a room temperature
E1820 test, including the option of DCPD crack measurement. Section 4 provides
detailed descriptions of each of the testing software menus and displays in the order in
Page 9 of 148
NLFT Testing - Series 2015 - V3+.16.01
which they are typically opened by the user. Sections 5 through 8 detail use of the
analysis software, including testing playback.
This manual includes discussion of the E399 and E1820 standards only. Please contact
FTA for more details on using the NLFT software for E1921 testing and analysis.
Operation and troubleshooting of laboratory controllers and test frames are outside the
scope of this document: for guidance, users are encouraged to contact their equipment
manufacturers.
Page 10 of 148
NLFT Testing - Series 2015 - V3+.16.01
2.0 Installation Guide
2.1 Connecting the ADwin to the Controller and FTA-DCPD
The ADwin-Gold is factory-calibrated and configured for differential inputs, although
FTA can provide a calibration procedure upon request. The ADwin must be grounded
for use in conjunction with a test machine: it should be grounded to the system console
or the common ground of the controller (refer to the ADwin hardware manual Start Up
section for details).
2.1.1 ANALOG INPUT AND OUTPUT CONNECTIONS
For fracture toughness applications, the following analog BNC connections are required
(refer to ADwin hardware manual Connector section for details). Note that these
connections are different than those required by FTA’s previous testing applications.
load cell signal from the test controller: connects to the IN 1 connector on the
ADwin
external function generator input on the test machine controller: connects to the
OUT 1 connector on the ADwin
[for compliance] the displacement signal from the test controller or auxiliary
instrumentation: connects to the IN 2 connector on the ADwin.
[for DC potential drop] active probe amplifier output: connects to the IN 5
connector on the ADwin.
[for DC potential drop] reference probe amplifier output (if required): connects to
the IN 6 connector on the ADwin.
in addition, the ADwin’s IN3 and IN4 connectors may be used as auxiliary
channels for display and/or data logging
The software is configured for a 10 volt range. It is therefore recommended that only
active inputs be connected to the ADwin, since an unused displacement or DC potential
drop signal may have an off-scale output (greater than 10 volts). This condition
influences the analog input multiplexer settling time and may affect the readings of the
other channels.
Page 11 of 148
NLFT Testing - Series 2015 - V3+.16.01
2.1.2 DIGITAL INPUT AND OUTPUT CONNECTIONS
EXTERNAL FUNCTION GENERATION INPUT (OUT 1)
DISPLACEMENT SIGNAL (IN2)
LOAD CELL SIGNAL FROM TEST CONTROLLER (IN1)
ACTIVE DCPD (IN5)
REFERENCE DCPD (IN6)
CONTROLLER RUN STOP,
FTA-DCPD
POWER SUPPLY
CONTROLLER GROUND
PC USB
With each system, FTA supplies a 25-pin run-stop cable, which connects to CONN 2
(digital out) of the ADwin. Pins 5 and 13 of this connector (short red and black wires)
monitor the run state of the controller (pin 5 connects to ‘high’ and pin 13 to ‘low/ground’
of a digital-in logic signal – else, the wires are interchangeable). The nine-pin connector
goes to the back of the FTA-DCPD power supply if required. See Section 2.2 for FTADCPD hook-up.
An ADwin connection diagram appears below:
Page 12 of 148
NLFT Testing - Series 2015 - V3+.16.01
2.2 Connecting the FTA-DCPD Current Supply and Amplifier
The figure below shows the front panel of the power supply. Programming functions are
activated by the keypad (see the DCPD options described in the test procedure in
Section 3.2 of this manual for details). The voltage/current output on the lower left side
has been disabled.
On the back of the unit, the current output is located on the left side beneath the 120
volt AC power cord. Use the FTA-provided current wire from the Current Out connector
to the test specimen or terminal strip. A cable-tie strain relief is recommended. On the
upper right side of the unit is a 9-pin connector labeled DCPD control, which is
connected to the nine-pin connector from the 25-pin CONN 2 connector on the cabling
to the ADwin-Gold. Note that pin 25 of CONN 2 goes to pin 1 of DCPD control; pin 1 of
CONN 2 goes to pin 3 of DCPD control, and pin 14 of CONN 2 goes to pin 2 of DCPD
control. Do not use the voltage/current outputs on the right side below the DCPD
control connector. Grounding of the unit is provided through the AC power cord.
However, an additional chassis ground terminal is provided next to the power cord and
use of that additional ground is recommended. FTA provides ground cabling in all
shipments.
Page 13 of 148
NLFT Testing - Series 2015 - V3+.16.01
On the FTA DCPD amplifier, gain selection and auto zero are provided using the panel
controls on the Ectron modules. The two shielded Input connectors above the toggle
switches (left and right) connect to the active and reference probes. The active probe
senses the voltage drop across the crack while the reference probe senses the voltage
drop at a location not significantly affected by crack growth. The left-side Ectron module
is linked to the left-side connector and the right-hand module is linked to the right-side
connector. Active/reference assignment is at the discretion of the user.
The two BNC Output connectors below the toggle switches are the amplified and
conditioned voltage outputs for the active and reference probes respectively. They are
each paired with the shielded connector above. The channel designated ‘active’ by the
user connects with IN5 on the ADwin-Gold. The channel designated ‘reference’ by the
user connects with IN6 on the ADwin-Gold.
The toggle switch between the Input and BNC Output connectors is the Filter Switch
for each channel. Filter ‘out’ is the down position, filter ‘in’ is the up position.
Page 14 of 148
NLFT Testing - Series 2015 - V3+.16.01
On the back panel of the amplifer may be found the illuminated power switch; a fuse
holder with a 2-amp fuse; and a 12-volt DC power cord. A 120-volt AC to 12-volt DC
power supply is provided with the system.
To the left of the DC power cord is a ground terminal. The unit must be connected to
ground to function properly: FTA provides ground cabling in all shipments.
Note that the unit is ready for operation only after all the cables have been installed.
This includes attaching the potential drop and current wires to the specimen. In addition,
the FTA DCPD testing software must be open and all test parameters entered before
the system’s power is turned on. Activation of the FTA software sends a logic signal to
the DC power supply enabling the polarity switching relays to start in the forward
position. Detailed instructions for use of the FTA-DCPD system are included in the test
procedure provided in Section 3.2 of this manual.
2.3 PC Setup and Installation of the FTA Software
1. Deactivate the computer’s power saving modes, including standby and
hibernation. The settings of the Windows display should be high color, 800 by
600 pixels (small fonts) or 1024 by 768 (large fonts). The Theme/Appearance
should be set to Windows Classic, regardless of the computer’s OS.
2. From the FTA CD, execute the three setup files for Testing, Analysis, and
Testing Playback from their respective folders. It is recommended the software
be permitted to create the default directories of c:\Program Files\NLFT Testing
and c:\Program Files\NLFT Analysis.
3. Each program can now be launched from the Start Programs menu. To launch
the applications from the desktop, right click on their filename in the Start
Programs menu and Send them to the desktop (create shortcut). Icon files
FTAlogo3.bmp or FTAlogo4.bmp may be used for customization. These icons
can be found in the NLFT Testing folder in the Programs directory.
Page 15 of 148
NLFT Testing - Series 2015 - V3+.16.01
2.4 Installing the ADWin Drivers on the PC
Use the ADwin drivers contained on the FTA-provided CD rather than the gold-colored
CD provided with the ADwin. Version 3.20.1200 should be used for 32-bit systems with
Windows 98 through Windows XP; for Windows 7 use version 5.00.10.00. Users of
older Adwins with ISA-link-to-USB adaptors must use the ADwin driver version
3.00.2332. Adwin drivers for 64-bit systems can be provided by FTA or found on the
web at www.adwin-downloads.de.
Copy the entire ADwin folder onto the PC desktop and carry out installation from there.
Before installing the drivers, connect the ADwin (powered off) to the computer.
1. Run the installation program in the ADWin folder. From the ADWin splash
screen, execute the complete Driver and ADbasic setup.
2. V. 3.20.1200 users will be prompted to restart the computer at this point. Do not
do so. Return to the splash screen, choose Developer-Software setup, and
repeat installation. Exit the installation program.
3. Restart the computer with the ADwin powered off.
4. Power up the ADwin. When prompted by the ‘new hardware wizard’, choose to
find the drivers from a specific location. Go the ADwin folder on the desktop and
choose to search. Ignore warnings about Windows logo testing and finish the
installation.
5. The installation window will reappear when this first stage of installation is
complete. Click ‘next’, choose not to search the internet, and continue with all
defaults.
6. Next, go to Start\Programs\ADwin\ADconfig. For v. 3.20.1200, remove the two
default ‘Link’ type connections. Add USB from the drop-down menu and click OK
to exit the form.
Page 16 of 148
NLFT Testing - Series 2015 - V3+.16.01
For v. 5.00.10.00, on the ADconfig screen choose ‘Add USB’ from the menu
across the top. Choose Device #150 [hex] and USB Serial #0.
7. Double click on the Adbasic icon on the computer desktop. Leave the license key
blank and click ‘OK’ twice to open the ADbasic program. For v. 3.20.1200, go
straight to step 8. For v. 5.00.10.00, go to the ‘options’ tab at the top of the
window and choose ‘compiler’. Make sure ‘System’ = ADwin Gold; ‘Processor’ =
T9; and ‘Device No.’ = 150 Hex. Close the window.
8. Press the red ‘B’ button on the Adbasic screen to boot the ADWin.
9. A flashing green LED on the ADwin-Gold unit means a successful connection
has been established. Unless the hardware is changed, booting the system from
this point forward will be done automatically when the FTA testing software is
opened.
10. The final installation may be confirmed by viewing the following form in the
Windows’ Device Manager.
Page 17 of 148
NLFT Testing - Series 2015 - V3+.16.01
2.5 Testing in Simulation
Note that it is possible to disconnect the ADwin from the test machine and operate the
NLFT program in simulation mode. Thus, users may familiarize themselves with the
FTA software and evaluate operation of the system without endangering the test
machine or expensive specimens. See Section 3.2 of this manual for sample test
procedures.
To simulate a compliance test, use BNC cables to jumper the ADwin’s OUT 1 to IN 1
and IN 2. To simulate a DCPD test, jumper OUT 1 to IN 1 and connect PIN 1 of
connector 2 to both of the center posts only of [PD active] IN 5 and [PD reference] IN 6.
Run the program as normal: new users may benefit from experimenting with the sample
test procedures provided in Section 3.2 of this manual.
2.6 Tuning
Make sure the machine controller is in displacement (actuator) control. Tune the system
as you normally would for a displacement controlled test. Since loading is static, some
dither might be required.
Page 18 of 148
NLFT Testing - Series 2015 - V3+.16.01
3.0 Using the NLFT Testing Software
The following section of this manual opens with a discussion of the six file-types
associated with the testing program. Section 3.2 contains an illustrative test procedures,
which detail the use of both the compliance and DCPD testing software. Analysis of test
results is covered in sections 5 through 8.
3.1 Understanding Testing Files
It is important to note that six different types of file are associated with the testing
program, each with its own extension. Some of these files are created automatically
during testing, while others must be configured and saved by the user. Several are
required by the FTA analysis software. Procedures for using these files are detailed
throughout this manual, but a summary of the different files is given briefly, for
information, below.
Test Parameter file (.pr5 extension): key information unique and necessary to
the test, such as specimen dimensions and initial test conditions. Although the
information is required, the files themselves are optional, and may be loaded,
modified and saved by the user for ease of use.
General Information file (.gn2 extension): general information not required for
testing, but that may be common across tests (such as test temperature or
material description). These optional files may be loaded, modified and saved by
the user. General information may also be added at analysis time.
Log file (.log extension): details of the test including test parameters and data
that are part of the analysis file (.in5). A log file is appended, rather than
overwritten, every time it is saved. See Appendix B1 for a description of log files.
Analysis file (.in5 extension): data required for the Windows Visual BASIC
analysis software. See Appendix B2.
Unloading Data file (.unl extension): calibration factors and the voltages of the
load-displacement unloading slopes. See Appendix B3.
Raw Data file (.raw extension): load-displacement information including elapse
time; load; displacement; and auxiliary channel information recorded in
engineering units. See Appendix B4.
Page 19 of 148
NLFT Testing - Series 2015 - V3+.16.01
3.2 Running a Test Using the FTA NLFT Software
The following is a general outline illustrating use of the FTA software to conduct a nonlinear fracture toughness test (E1820) at room temperature, using both a clip gage and
DC potential drop. These steps are meant as guidelines only in order to demonstrate
use of the FTA testing software. For detailed descriptions of the menus and forms
referred to below, see Section 4 of this manual. For an analysis procedure, see Section
5.3.
Note that when data are entered in a text box on a program menu, the data are not
transferred to the corresponding variable until another text box or command button
(such as Send to DSP) is clicked. If data have been entered in a text box but Send to
DSP has not been clicked, a blinking red reminder message will appear.
The following step-by step guide to test execution applies both to compliance and
DCPD testing. Where the process differs, directions for compliance testing appear in
blue and directions for DCPD testing appear in red. These steps are a guideline only: a
thorough knowledge of governing ASTM standards is essential.
3.2.1 SETUP
1. Turn on power to the ADwin.
2. Power to the FTA-DCPD amplifer and power supplies should be on, but the
power supply’s Output (number 1 on keypad) should be toggled to Off (the
front LED panel on the power supply should display ‘Output Off’). The unit will
start with a default voltage of 5 volts, which is recommended for most
applications. The default current is 1 amp. With Output set to off, the current
may be changed using the keypad. To input a current of 10 amps, for example,
press CURR (number 8 on the keypad) to bring up a new menu. Press the
numbers 1 and 0. Press the blue ENTER key to confirm the new setting.
3. On the FTA-DCPD amplifer, set the desired gain with the black dial on the
appropriate Ectron module (left module for left channel, right module for right
channel). Remember that the actual gain is 10 times that displayed on the
module. Also ensure that the amplifier’s VERN toggle switch is in the OUT
position and the left-hand toggle switch is in the X1 position. Note that the
toggle switch for the excitation has been locked in the 5 volt position. Do not
tamper with this lockout.
4. Open the NLFT testing program. If the program is already open from a previous
test, skip straight to step 7 of this procedure. Ensure the green light on the
Adwin is blinking, which indicates communication with the computer. Reboot
the Adwin to establish communication, if necessary. On the initial Splash
Screen, choose the crack monitor type: Compliance (for clip gage
Page 20 of 148
NLFT Testing - Series 2015 - V3+.16.01
measurement of crack length and J) or DC Potential Drop (for DCPD
measurement of crack length and clip gage measurement of J).
5. Select New Test (select Resume only if restarting a test, for example, after a
system crash).
6. The Main Menu appears: select Unit Type (English or Metric).
7. From the Input menu, select Data from the dropdown list. The Data Input form
appears, with the Initialize tab foremost. Note that the form has six tabs, which
are typically addressed from left to right.
If the program is already open from a previous test, ensure
FNG OUT on the Status screen reads zero. Ensure STOP
is active on the Ramp Generator and that the three boxes
under Data Acquisition Status are unticked. On the
Initialize tab of the Data Input form, Initialize the new test
by ticking Set Delta a to Zero and Clear Data Storage
Buffer. Press Send to DSP to clear the Adwin of data from
the previous test.
8. Select the Initialize tab of the Data Input form and enter the Test ID.
9. Press Start Data Files: this enables you to save .log files; .unl files (compliance
only); and .raw files as well as specify their data storage path.
10. Press Load Test Parameters (.pr2 files for common specimen geometries may
be found in the NLFT testing program directory).
11. Ensure the K-Calibration Type and PD Calibration Type are appropriate for
the application.
12. The Send to DSP button will blink when changes are made, reminding you to
send the changes to the ADwin by pressing Send to DSP. As an option, press
Print to Log to send data input to the .log file.
13. Address the remaining five tabs on the Data Input form (details may be found
in Section 4 of this manual). Go first to the Coefficients tab and confirm correct
values.
14. Go to the Dimensions tab. Ensure values are correct and change as
necessary. The program will automatically calculate limit load based upon the
values entered. The limit load is based on the plastic limit derived from the
specimen’s yield strength and geometry and is useful for determining the
maximum load range for the test.
15. Address the Calibration tab. Review and adjust values as required. It is
important to note that values in red must correspond to settings on the
controller and PD instrumentation. A full scale of 10 volts is assumed for all
controller settings and entry must be 10% of full-scale range. For a load range
Page 21 of 148
NLFT Testing - Series 2015 - V3+.16.01
of 25,000 lbs, for example, the entry in the Load Cell Calibration text box
should be 2500. PD gain (if running a DCPD test) should be the same as the
gain set on the FTA amplifier x10 (a gain of 500 on the amplifier should be
entered as 5000 on the Calibration tab). Initial PD should be set to zero.
16. Select the Data Acquisition tab, on which criteria for and characteristics of
automatic unloading slopes or DCPD crack length measurements are
determined. For example, if Load under Unloading Slope/DCPD Acquisition
Interval is set to 500 pounds, then that action will be taken every time the load
increases by 500 pounds. Please see Section 4.4.1.5 for more details on the
Data Acquisition tab.
17. Go to the Limits tab. The parameters on this tab specify the limits (Transducer
Limits, Load Drop Limit) at which the command signal will go to STOP or the
test will be terminated (Delta a Limit).
Load Limit Hold determines the initial ramp-up load level (which in most
cases should not exceed the Pmax of the precrack), at which point the
system can be tested for signal quality and correct crack-length reading
before the start of the test proper.
Ramp Down Amount specifies how much the load will ramp down upon
test termination (before going into Hold mode).
Automatic Preload is a useful alternative to the controller setpoint and
applies a [typically low] constant load to the specimen when, for
example, it is coming to test temperature or being held steady for other
purposes before testing commences.
18. Press Send to DSP to send all changes on the Data Input form to the ADwin.
Print to Log.
19. Return to the Initialize tab and press Save Test Parameters. This updates the
.pr2 file for future use.
20. Minimize the Data Input form, but do not close it.
21. Return to the Main Menu and select the Options form from the Input
dropdown list. The default settings are appropriate for most applications. Apply
Rotation Correction to Delta a should always be ticked when compliancetesting a C(T) specimen. For bend-bar testing, Normal Load Cell Polarity and
Normal Stroke Polarity should be unticked. See Section 4.4.2.2 for more
details on the Options menu.
22. Press Send to DSP regardless of whether any changes have been made.
Minimize but do not close the Options menu.
23. Return to the Main Menu and select General Information from the Input
dropdown list. Load a previously-saved .gn2 file or input new values and save
the file for future use. Information about both the test and precracking regime
Page 22 of 148
NLFT Testing - Series 2015 - V3+.16.01
can be recorded. Note that some precracking parameters are necessary for
fulfilling validity requirements during analysis. The General Information form
may be closed before proceeding.
24. Return to the Main Menu and open the Ramp Generator from the Control
drop-down list. The Ramp Generator is the form from which the test is
controlled and must not be closed while the test is running. Changes on this
form are sent immediately to the ADwin.
25. On the Ramp Generator, verify the Ramp and Data Acquisition Rates and
change as appropriate (see details in Section 4.5). These rates may also be
changed on-the-fly while the test is running, if necessary. Ensure once again
that none of the check-boxes is selected and that the program is in STOP
mode. Minimize but do not close the Ramp Generator.
26. Return to the Main Menu and open the Status; Load-displacement; and J-da
(J-delta a) forms from the Display drop-down list.
27. Observe the Status display. Verify that the load and displacement channels are
active and reading correctly. FNG Out should read zero. Load should also
indicate zero.
28a. COMPLIANCE ONLY. Set the test controller to stroke control. Turn on the test
machine hydraulics. Enable the external command for full-scale input. Mount
the specimen in the test machine. Attach the clip gage and use the controller to
adjust the signal to read zero (Disp 1 on the FTA testing software’s Status
display). If more than 10v will be required for the test, adjust the signal for a
negative voltage.
28b. DCPD ONLY. Set the test controller to stroke control. Turn on the test machine
hydraulics. Enable the external command for full-scale input. Mount the
specimen in the test machine. Attach the clip gage and use the controller to
adjust the signal to read zero (Disp 1 on the FTA testing software’s Status
display). If more than 10v will be required for the test, adjust the signal for a
negative voltage.
Attach current and potential drop leads to the specimen.
With the FTA-DCPD power supply Output still Off, zero the volts on the Status
screen by toggling up the ‘auto/man zero’ switch at the top left of the amplifier’s
Ectron module. When the red light has activated, return the switch to its central
position. Voltage should now read zero on the NLFT testing software’s Status
screen (DCPD volts).
Page 23 of 148
NLFT Testing - Series 2015 - V3+.16.01
Activate the current output, (OUT ON/OFF or keypad number 1 on the power
supply). If the FTA software is running and the sample installed correctly, the
LED display should appear similar to the figure below, in which a 10 amp
current has been selected. In this figure, the voltage of 0.8686 volts is due
almost entirely to the voltage drop through the 10-12 AWG wire from the DC
power supply to the test sample. Constant current is assured as long as the
display voltage is less than the default setting of 5 volts. Note that in addition to
displaying the designated current of ~10 amps, the left side of the display
shows a square symbol next to the letters ‘CC’, indicating the constant current
mode.
The figure below shows the power supply display if the current wires are not
hooked up to the specimen or the FTA software is not running. Note that the left
side of the display shows a square symbol next to the letters ‘CV’, indicating the
constant voltage mode. If the system cannot maintain constant current due to
the resistance of the current loop then it defaults to the constant voltage mode.
The constant voltage mode with a current value lower than desired is most
likely due to insufficient wire size in the current path. A current value near zero
Page 24 of 148
NLFT Testing - Series 2015 - V3+.16.01
indicates an open current path or a low logic signal state on pins 2 and 3 of the
DCPD control connector.
Using the black knob on the amplifier’s Ectron module(s), adjust the gain
setting such that the amplified signal displayed on the NLFT testing software’s
Status screen is between 0.5 and 1.0 volts. Be sure to enter the final gain
setting in the FTA software on the Calibration tab, remembering to multiply the
selected amplifier gain by 10. (Note that the proper gain setting is also a
function of the applied current and must take into account the actual PD
calibration and range of crack size. It is important not to reach the ±10 volt
amplifier output limit during a crack growth rate experiment). For gains above
10,000, select the VERN IN position of the toggle switch. The vernier
adjustment can be used to increase the gain to ~25,000.
3.2.2 RUNNING THE TEST
1. Press Reset MAX on the Status form to reset the FNG Out and Load on the
Status display.
2. Return to the Ramp Generator and Clear Message if necessary.
3. Press Run on the Ramp Generator to activate the command signal.
4. Press Load Limit Hold to ensure that loading will stop when the load limit (set
on the Limits tab of the Data Input form) is reached.
5. Press Load-Displacement to begin data acquisition and ensure real-time
plotting of load on the Load-Displacement Display.
6. Press Ramp Up to begin loading the specimen to the load limit hold level.
Page 25 of 148
NLFT Testing - Series 2015 - V3+.16.01
7. Observe the Load-displacement display and Status screen (Load) to ensure
loading stops at the load limit hold. The HOLD indicator on the Ramp
Generator will flash when the load limit has been reached. The Loaddisplacement display may be scaled using the blue buttons.
8a. COMPLIANCE ONLY. Return to the Ramp Generator. Press the blue Unload
Slope button once to apply an unload slope to the specimen (the
characteristics of the unload slope were determined on the Data Acquisition
tab of the Data Input menu). Observe the green trace on the Load-
displacement display to verify correct operation:
the correlation coefficient should 0.9999 or better
the crack length should be accurate
Repeat unloading slopes as necessary to ensure repeatability of crack length
and quality of signal. Scale the unloading slopes as necessary (using the pink
buttons). Press Refresh to bring up the full display. Delta a should be within ±
0.001 inches and there should be no change in Ci/Co greater than 0.003. When
the system is stable, tick Set Delta a to Zero on the Initialize tab of the Data
Input form. Send to DSP.
Activate Unloading Slope on the Ramp Generator (Data Acquisition Status)
and apply one more unload slope to the specimen. This will be the first active
data point in the .in5 file.
8b. DCPD ONLY. Return to the Ramp Generator. Press the blue DCPD Acqu.
button once to take a DCPD reading (the characteristics of the acquisition were
determined on the Data Acquisition tab of the Data Input menu). Observe the
green trace on the Load-displacement display to verify correct operation.
Press DCPD Acqu. several more times. Observe the DCPD Active Voltage on
the Load-Displacement Display form. Readings should be consistent within
0.1%. Compute the mean of the final three readings and enter the value as
Initial PD on the Calibration tab of the Data Input form. Send to DSP.
Activate another DCPD acquisition cycle. The Load-Displacement Display
should now indicate the correct crack length. Apply at least two more cycles
and observe changes in crack length. Verify that the variation in delta a is
consistently within ±0.001 inches.
Page 26 of 148
NLFT Testing - Series 2015 - V3+.16.01
Activate DCPD Data on the Ramp Generator (Data Acquisition Status) and
press DCPD Acqu. once more. This will be the first active data point in the .in5
file.
9. When the quality of the signal and repeatability of crack length readings is
satisfactory, it is time to start the test. On the Ramp Generator disable Load
Limit Hold. Enable Auto Unloading [compliance] [or] Enable Auto DCPD Acq.
[DCPD] and press Clear Message.
10. Press Ramp Up to start the test. Unload slopes/DCPD acquisition cycles will
occur at the intervals and durations set on the Data Acquisition tab of the
Data Input form. View the Load-Displacement trace to verify correct
operation.
11. Observe the J-da (J-delta) display from the Display and adjust the scale as
required.
12. When the final test limit has been achieved (typically the Delta a Limit
specified on the Limits tab of the Data Input form), the test is complete. The
machine will automatically ramp down to the load specified under Ramp Down
Amount on the Limits tab. When this load is reached, the test will HOLD.
13. On the Ramp Generator, disable Unloading Slope and Auto Unloading/DCPD
data and Auto DCPD Acqu. On the Limits tab of the Data Input form, disable
Displacement 1 Limit and Send to DSP.
14. Press Run and then Ramp Down to ramp the load to zero. When the load
reaches zero press Hold. Disable Load-Displacement and remove the
specimen from the test machine (if DCPD, turn off the current before removing
the specimen). If necessary, press Ramp Down again until FNG Out reads
zero on the Status display.
15. Press Stop.
16. Return to the Main Menu. Using the File drop-down list, save the analysis
(.in5) file in Version 3 Format. Also save the load-displacement (.raw) data file
and the unload (.unl) data file.
Page 27 of 148
NLFT Testing - Series 2015 - V3+.16.01
17. Choose Exit if you wish to quit the program. For a new test, return to the
Initialize tab on the Data Input form. Enter a new Test ID and go straight to
step 7 of the preceding section, Setup.
Page 28 of 148
NLFT Testing - Series 2015 - V3+.16.01
4.0 NLFT Testing Software: Description of Menus and Tabs
The following section of the manual offers a complete description of the menus and tabs
comprising both the compliance and potential drop NLFT testing applications. The
menus are presented in the order in which they would normally be opened during test
setup.
For a step-by-step procedure detailing how the software may be used for running an
E1820 test, see preceding Section 3.2.
4.1 Splash Screen
The splash screen is displayed upon start-up. The application title and version number
are identified at the top of this form. From this form the Crack Monitor type
(Compliance or DC Potential Drop) is selected. If a different crack monitor type is
required for subsequent tests, the program must be shut down completely and
restarted. Simultaneous Compliance and DC Potential Drop if desired.
Once the test selection has been made, select New Test to call up the Main Menu and
begin a test from scratch. The Resume options allows the operator to resume a test
that may already have been in progress (for example, after a system crash or power
outage). See Appendix A for details. The establishment of a successful link between the
PC and the ADwin is confirmed when the green LED on the Adwin begins to flash.
Page 29 of 148
NLFT Testing - Series 2015 - V3+.16.01
4.2 Main Menu
The Main Menu is always displayed while the program is running: its default position is
in the upper left-corner of the computer screen. The Unit Type (English or Metric)
must be selected before other forms may be opened. The Unit Type can be changed
while the test is in progress or the program is open, but such a change requires closing
and reopening all of the other forms. Note that all processing and data storage are done
in English units, even if the Metric option is chosen: the unit conversion takes place as
data are entered or displayed.
The Work Load displays the ADwin workload in % for both high and low priority
processes and is for reference only.
Pressing the red STOP DSP button terminates all DSP processes. This is not
recommended for normal operation and the button is disabled by default. To activate,
tick the Enable Stop box. Sometimes, if the ADwin does not appear to be responding,
enabling stop can reset the Adwin so normal functioning can resume. All DSP
processes are then restarted when the Run Button is pressed on the Main Function
Generator. Use with caution.
4.3 File
The first drop-down menu on the Main Menu is File. See Section 3.1 of this manual for
a full discussion of the files produced by the testing software.
4.3.1 SAVE ANALYSIS FILE
Analysis files with the .in5 extension must be saved manually, although they are held in
memory until the data buffer has been cleared. The user may save the analysis file at
any time during the test, noting that saving an analysis file overwrites any previous
versions.
Page 30 of 148
NLFT Testing - Series 2015 - V3+.16.01
Loading...