MTS 656-06 User Manual

Triaxial Cell Product Information

Models 656.04, 656.05, and 656.06

015-025-501 B be certain.

©

2014MTS Systems Corporation. All rights reserved.

Original Instructions (English): 015-025-501 B—January 2014

Trademark Information

MTS, be certain., Bionix, ElastomerExpress, FlatTrac, FlexTest, Just In Case, LevelPlus, MTS Criterion,
MTS EM Extend, MTS Insight, MTS Landmark, RPC, ServoSensor, SWIFT, Temposonics, TestWare,
TestWorks are registered trademarks of MTS Systems Corporation within the United States. Acumen,
Advantage, Aero ST, Aero-90, AeroPro, Criterion, CRPC, Echo, Flat-Trac, Landmark, MAST,
MicroProfiler, MPT, MTS Acumen, MTS Echo, MTS Fundamentals, MTS TestSuite, ReNew, SilentFlo,
TempoGuard, TestLine, and Tytron are trademarks of MTS Systems Corporation within the United
States. These trademarks may be registered in other countries. All other trademarks are property of
their respective owners. All other trademarks are property of their respective owners.

Proprietary Software

Software use and license is governed by the MTS End User License Agreement which defines all
rights retained by MTS and granted to the End User. All Software is proprietary, confidential, and
owned by MTS Systems Corporation and cannot be copied, reproduced, disassembled, decompiled,
reverse engineered, or distributed without express written consent of MTS.

Software Verification and Validation

MTS software is developed using established quality practices in accordance with the requirements
detailed in the ISO 9001 standards. Because MTS-authored software is delivered in binary format, it
is not user accessible. This software will not change over time. Many releases are written to be
backwards compatible, creating another form of verification. The status and validity of the MTS operating
software is also checked during system verification and routine calibration of MTS hardware. These
controlled calibration processes compare the final test results after statistical analysis against the
predicted response of the calibration standards. With these established methods, MTS assures its
customers that MTS products meet exacting quality standards when initially installed and will continue
to perform as intended over time.

Manual Part Number—Publication Date—Release

015-025-501 A—June 1992

Table of Contents

Technical Support

How to Get Technical Support.........................................................................................................................5

Before You Contact MTS.................................................................................................................................5

If You Contact MTS by Phone.........................................................................................................................7

Problem Submittal Form in MTS Manuals......................................................................................................8

Preface

Before You Begin.............................................................................................................................................9

Documentation Conventions............................................................................................................................9

Safety

General Safety Practices.................................................................................................................................14

Safety Practices Before Operating the System...............................................................................................14

Safety Practices While Operating the System ...............................................................................................19

Hazard Labels.................................................................................................................................................21

Crunch Zones and Pinch Points.....................................................................................................................22

Table of Contents

Introduction

Introduction....................................................................................................................................................24

Description.....................................................................................................................................................24

Triaxial Cell Specications............................................................................................................................32

Operation

Operation........................................................................................................................................................36

Moving and Mounting the Bell......................................................................................................................36

Performing Tests.............................................................................................................................................37

Prepare the Specimen for Pore Pressure/Extension Tests..................................................................37

Prepare the Specimen for Compression Tests....................................................................................39

Raise and Lock the Bell......................................................................................................................40

Install the Specimen for Extension/Pore Pressure Tests....................................................................42

Install the Specimen for a Compression Test.....................................................................................47

Pressurize the Triaxial Cell................................................................................................................50

Remove the Old Specimen.................................................................................................................54

Changing Between Extension/Pore Pressure and Compression Test Setups.................................................62

Changing to a Compression Test Setup..............................................................................................63

Raise and Lock the Bell..........................................................................................................64

Change the Force Transducer.................................................................................................66

3

Table of Contents

Maintenance

Maintenance...................................................................................................................................................84

Install the Spherical Platen.....................................................................................................69

Plug the Ports.........................................................................................................................70

Changing to an Extension-Pore Pressure Test Setup..........................................................................72

Raise and Lock the Bell..........................................................................................................73

Remove the Spherical Platen..................................................................................................75

Change the Force Transducer.................................................................................................76

Unplug Lines..........................................................................................................................79

4

Technical Support

How to Get Technical Support

Start with your manuals

The manuals supplied by MTS provide most of the information you need to use and maintain your equipment.
If your equipment includes software, look for online help and README files that contain additional product
information.

Technical support methods

MTS provides a full range of support services after your system is installed. If you have any questions
about a system or product, contact Technical Support in one of the following ways.

Web site

Outside the U.S.

For technical support outside the United States, contact your local sales and service office. For a list of
worldwide sales and service locations and contact information, use the Global MTS link at the MTS web
site:

www.mts.com > Global Presence > Choose a Region

www.mts.com > Contact Us (upper-right corner) > In the Subject field, choose
To escalate a problem; Problem Submittal Form

Worldwide: [e-mail]-mail

Europe: [e-mail]

Worldwide: 1 800 328 2255 - toll free in U.S.; [phone] - outside U.S.Telephone

Europe: [phone], International toll free in Europe

Before You Contact MTS

MTS can help you more efficiently if you have the following information available when you contact us for
support.

Know your site number and system number

The site number contains your company number and identifies your equipment type (such as material
testing or simulation). The number is typically written on a label on your equipment before the system
leaves MTS. If you do not know your MTS site number, contact your sales engineer.

Example site number: 571167

Triaxial Cell Product Information | 5

Technical Support

When you have more than one MTS system, the system job number identifies your system. You can find
your job number in your order paperwork.

Example system number: US1.42460

Know information from prior technical assistance

If you have contacted MTS about this problem before, we can recall your file based on the:

• MTS notification number

• Name of the person who helped you

Identify the problem

Describe the problem and know the answers to the following questions:

• How long and how often has the problem occurred?

• Can you reproduce the problem?

• Were any hardware or software changes made to the system before the problem started?

• What are the equipment model numbers?

• What is the controller model (if applicable)?

• What is the system configuration?

Know relevant computer information

For a computer problem, have the following information available:

• Manufacturer’s name and model number

• Operating software type and service patch information

• Amount of system memory

• Amount of free space on the hard drive where the application resides

• Current status of hard-drive fragmentation

• Connection status to a corporate network

Know relevant software information

For software application problems, have the following information available:

• The software application’s name, version number, build number, and (if available) software patch
number. This information can typically be found in the About selection in the Help menu.

• The names of other applications on your computer, such as:

— Anti-virus software

— Screen savers

— Keyboard enhancers

— Print spoolers

6 | Triaxial Cell Product Information

Technical Support

— Messaging applications

If You Contact MTS by Phone

A Call Center agent registers your call before connecting you with a technical support specialist. The agent
asks you for your:

• Site number

• Name

• Company name

• Company address

• Phone number where you can be reached

If your issue has a notification number, please provide that number. A new issue will be assigned a unique
notification number.

Identify system type

To enable the Call Center agent to connect you with the most qualified technical support specialist available,
identify your system as one of the following types:

• Electrodynamic material test system

• Electromechanical material test system

• Hydromechanical material test system

• Vehicle test system

• Vehicle component test system

• Aero test system

Be prepared to troubleshoot

Prepare to perform troubleshooting while on the phone:

• Call from a telephone close to the system so that you can implement suggestions made over the phone.

• Have the original operating and application software media available.

• If you are not familiar with all aspects of the equipment operation, have an experienced user nearby to
assist you.

Write down relevant information

In case Technical Support must call you:

• Verify the notification number.

• Record the name of the person who helped you.

Triaxial Cell Product Information | 7

Technical Support

• Write down any specific instructions.

After you call

MTS logs and tracks all calls to ensure that you receive assistance for your problem or request. If you
have questions about the status of your problem or have additional information to report, please contact
Technical Support again and provide your original notification number.

Problem Submittal Form in MTS Manuals

Use the Problem Submittal Form to communicate problems with your software, hardware, manuals, or
service that are not resolved to your satisfaction through the technical support process. The form includes
check boxes that allow you to indicate the urgency of your problem and your expectation of an acceptable
response time. We guarantee a timely response—your feedback is important to us.

You can access the Problem Submittal Form at www.mts.com > Contact Us (upper-right corner) > In the

Subject field, choose To escalate a problem; Problem Submittal Form

8 | Triaxial Cell Product Information

Preface

Before You Begin

Safety first!

Before you use your MTS product or system, read and understand the safety information provided with
your system. Improper installation, operation, or maintenance can result in hazardous conditions that can
cause severe personal injury or death, or damage to your equipment and specimen. Again, read and
understand the safety information provided with your system before you continue. It is very important that
you remain aware of hazards that apply to your system.

Other MTS manuals

In addition to this manual, you may receive additional manuals in paper or electronic form.

You may also receive an MTS System Documentation CD. It contains an electronic copy of the manuals
that pertain to your test system.

Controller and application software manuals are typically included on the software CD distribution disc(s).

Documentation Conventions

The following paragraphs describe some of the conventions that are used in your MTS manuals.

Hazard conventions

Hazard notices may be embedded in this manual. These notices contain safety information that is specific
to the activity to be performed. Hazard notices immediately precede the step or procedure that may lead
to an associated hazard. Read all hazard notices carefully and follow all directions and recommendations.
Three different levels of hazard notices may appear in your manuals. Following are examples of all three
levels. (for general safety information, see the safety information provided with your system.)

Danger:

Danger notices indicate the presence of a hazard with a high level of risk which, if ignored,
will result in death, severe personal injury, or substantial property damage.

Triaxial Cell Product Information | 9

Preface

Warning:

Warning notices indicate the presence of a hazard with a medium level of risk which, if ignored,
can result in death, severe personal injury, or substantial property damage.

Caution:

Caution notices indicate the presence of a hazard with a low level of risk which, if ignored,
could cause moderate or minor personal injury or equipment damage, or could endanger test
integrity.

Other special text conventions

Important:

Important notices provide information about your system that is essential to its proper
function. While not safety-related, if the important information is ignored, test results may
not be reliable, or your system may not operate properly.

Note:

Notes provide additional information about operating your system or highlight easily
overlooked information.

Recommended:

Recommended notes provide a suggested way to accomplish a task based on what MTS
has found to be most effective.

Tip:

Tips provide helpful information or a hint about how to most efficiently accomplish a task.

Access:

Access provides the route you should follow to a referenced item in the software.

Examples show specific scenarios relating to your product and appear with a shaded
background.

Special terms

The first occurrence of special terms is shown in italics.

Illustrations

Illustrations appear in this manual to clarify text. They are examples only and do not necessarily represent
your actual system configuration, test application, or software.

10 | Triaxial Cell Product Information

Preface

Electronic manual conventions

This manual is available as an electronic document in the Portable Document File (PDF) format. It can be
viewed on any computer that has Adobe Acrobat Reader installed.

Hypertext links

The electronic document has many hypertext links displayed in a blue font. All blue words in the body text,
along with all contents entries and index page numbers, are hypertext links. When you click a hypertext
link, the application jumps to the corresponding topic.

Triaxial Cell Product Information | 11

Safety

Topics:

•

General Safety Practices...................................................................................................................14

•

Safety Practices Before Operating the System.................................................................................14

•

Safety Practices While Operating the System ..................................................................................19

•

Hazard Labels...................................................................................................................................21

•

Crunch Zones and Pinch Points........................................................................................................22

Triaxial Cell Product Information | 13

Safety

General Safety Practices

If you have system related responsibilities (that is, if you are an operator, service engineer, or maintenance
person), you should study this manual carefully before you attempt to perform any test system procedure.

You should receive training on this system or a similar system to ensure a thorough knowledge of your
equipment and the safety issues that are associated with its use. In addition, you should gain an
understanding of system functions by studying the other manuals supplied with your test system. Contact
MTS for information about the content and dates of training classes that are offered.

It is very important that you study the following safety information to ensure that your facility procedures
and the system’s operating environment do not contribute to or result in a hazardous situation. Remember,
you cannot eliminate all the hazards associated with this system, so you must learn and remain aware of
the hazards that apply to your system at all times. Use these safety guidelines to help learn and identify
hazards so that you can establish appropriate training and operating procedures and acquire appropriate
safety equipment (such as gloves, goggles, and hearing protection).

Each test system operates within a unique environment which includes the following known variables:

• Facility variables (facility variables include the structure, atmosphere, and utilities)

• Unauthorized customer modifications to the equipment

• Operator experience and specialization

• Test specimens

Because of these variables (and the possibility of others), your system can operate under unforeseen
circumstances that can result in an operating environment with unknown hazards.

Improper installation, operation, or maintenance of your system can result in hazardous conditions that
can cause death, personal injury, or damage to the equipment or to the specimen. Common sense and a
thorough knowledge of the system’s operating capabilities can help to determine an appropriate and safe
approach to its operation.

Observe the prescribed safety practices before and during system operation.

It is the customer's responsibility to take the machine out of service and contact MTS Service if discrepancies
in system operation are found.

Safety Practices Before Operating the System

Before you apply power to the test system, review and complete all of the safety practices that are applicable
to your system. The goal, by doing this, is to improve the safety awareness of all personnel involved with
the system and to maintain, through visual inspections, the integrity of specific system components.

14 | Triaxial Cell Product Information

Safety

Read all manuals

Study the contents of this manual and the other manuals provided with your system before attempting to
perform any system function for the first time. Procedures that seem relatively simple or intuitively obvious
can require a complete understanding of system operation to avoid unsafe or dangerous situations.

Locate lockout/tagout points

Know where the lockout/tagout point is for each of the supply energies associated with your system. This
includes the hydraulic, pneumatic, electric, and water supplies (as appropriate) for your system to ensure
that the system is isolated from these energies when required.

Know facility safe procedures

Most facilities have internal procedures and rules regarding safe practices within the facility. Be aware of
these safe practices and incorporate them into your daily operation of the system.

Locate Emergency Stop buttons

Know the location of all the system Emergency Stop buttons so that you can stop the system quickly in
an emergency. Ensure that an Emergency Stop button is located within close proximity of the operator at
all times.

Know controls

Before you operate the system for the first time, make a trial run through the operating procedures with
the power off. Locate all hardware and software controls and know what their functions are and what
adjustments they require. If any control function or operating adjustment is not clear, review the applicable
information until you understand it thoroughly.

Have first aid available

Accidents can happen even when you are careful. Arrange your operator schedules so that a properly
trained person is always close by to render first aid. In addition, ensure that local emergency contact
information is posted clearly and in sight of the system operator.

Know potential crush and pinch points

Be aware of potential crush and pinch points on your system and keep personnel and equipment clear of
these areas.

An important consideration for servohydraulic systems is that when power is interrupted, it is likely that
stored accumulator pressure will persist for some time within the system. In addition, it is likely that as
stored energy dissipates, gravity will cause portions of the system to move.

Be aware of component movement with hydraulics off

For hydraulic systems, be aware that mechanical assemblies can shift or drift due to changes within
hydraulic hardware when hydraulics are turned off. This non-commanded movement is because oil can
transfer between the pressure and return ports and across internal components of the hydraulic hardware.
Be aware that this can happen, and clear the area around the mechanical assemblies when hydraulics
are turned off.

Triaxial Cell Product Information | 15

Safety

Know electrical hazards

When the system electrical power is turned on, minimize the potential for electrical shock hazards. Wear
clothing and use tools that are properly insulated for electrical work. Avoid contact with exposed wiring or
switch contacts.

Whenever possible, turn off electrical power when you work on or in proximity to any electrical system
component. Observe the same precautions as those given for any other high-voltage machinery.

Make sure that all electrical components are adequately grounded. Grounds must remain connected and
undisturbed at all times.

Ensure correct cable connection

If a system cable has been disconnected, ensure that you establish the correct cable-to-connector
relationship during reconnection. Incorrect cable connections can result in improper servo loop phasing
or an open servo loop condition, either of which can cause unstable or unexpected and potentially dangerous
system motions. Verify the correct cable-to-connector relationship by observing the cable and connector
labeling and the system wiring schematics.

Keep bystanders safely away

Keep bystanders at a safe distance from all equipment. Never allow bystanders to be in close proximity
of specimens or equipment while the test is running.

Wear proper clothing

Do not wear neckties, shop aprons, loose clothing or jewelry, or long hair that could get caught in equipment
and result in an injury. Remove loose clothing or jewelry and restrain long hair.

Remove flammable fluids

Remove flammable fluids from their containers or from components before you install the container or
component. If desired, you can replace the flammable fluid with a non-flammable fluid to maintain the
proper proportion of weight and balance.

Know compressed gas hazards

Your system may contain accumulators that require a high-pressure gas precharge (pressures that exceed
138 bar [2000 psi]). High-pressure devices are potentially dangerous because a great amount of energy
is available in the event of an uncontrolled expansion or rupture.

Observe the following safety practices when you work with high-pressure air or gases:

• When you charge an accumulator, follow all the charging instructions provided in the appropriate product
information manuals. When precharging accumulators, properly identify the type of gas to be used and
the type of accumulator to be precharged.

• Use only dry-pumped nitrogen to precharge nitrogen-charged accumulators. (Dry-pumped nitrogen
can also be labeled “oil pumped” or “dry water pumped.”) Do not use compressed air or oxygen for
precharging: the temperature increase caused by rapid gas compression can result in highly explosive
conditions when hydraulic fluid is in the presence of oxygen or compressed air.

• Always follow the recommended bleeding procedures before you remove or disassemble components
that contain pressurized gas. When you bleed a gas or remove a fitting, hose, or component that
contains a gas, remember that many gases cannot support life. Therefore, as the ratio of released gas
to oxygen increases, so does the potential for suffocation.

16 | Triaxial Cell Product Information

Safety

• Wear appropriate safety devices to protect your hearing. Escaping air or gas can create a noise level
that can damage your hearing.

• Ensure that all pressurized air or gas is bled out of a pneumatic or gas-charged device before you start
to disassemble it. A thorough understanding of the assembly and its pressurized areas is necessary
before you undertake any maintenance. Refer to the appropriate product information for the correct
bleeding procedure.

It may not be obvious or intuitive which bolts or fittings are used to restrain a pressurized area. On
some assemblies, you must remove a cover plate to gain access to the structural bolts. Sometimes, to
protect you from a rapid release of trapped gases, a small port is exposed when you remove this cover
plate. Exposing this port ensures that the gas precharge is fully bled before disassembly. However,
this is not the recommended procedure for bleeding a pneumatic or gas-charged device, because it
can expose you to the dangers of escaping compressed gas and particulates that are expelled from
the chamber or around the seals. Do not assume that cover plates and ports are installed in all the
critical locations.

Consult MTS when in doubt about the safety or reliability of any system-related procedure or modification
that involves devices that contain any type of compressed gas.

Check bolt ratings and torques

To ensure a reliable product, fasteners (such as bolts and tie rods) used in MTS-manufactured systems
are torqued to specific requirements. If a fastener is loosened or the configuration of a component within
the system is modified, see the system and component assembly drawings (located on the System
Documentation CD) to determine the correct fastener, fastener rating, and torque. Over torquing or under
torquing a fastener can create a hazardous situation due to the high forces and pressures present in MTS
test systems.

On rare occasions, a fastener can fail even when it is correctly installed. Failure usually occurs during
torquing, but it can occur several days later. Failure of a fastener can result in a high velocity projectile.
Therefore, it is a good practice to avoid stationing personnel in line with or below assemblies that contain
large or long fasteners.

Practice good housekeeping

Keep the floors in the work area clean. Industrial chemicals, such as hydraulic fluid, that are spilled on any
type of floor can result in a dangerous, slippery surface. Do not leave tools, fixtures, or other items not
specific to the test lying about on the floor, system, or decking.

Protect hoses and cables

Protect electrical cables from spilled fluids and from excessive temperatures that can cause the cables to
harden and eventually fail. Ensure that all cables have appropriate strain relief devices installed at the
cable and near the connector plug. Do not use the connector plug as a strain relief.

Protect all system hoses and cables from sharp or abrasive objects that can cause the hose or cable to
fail. Use a cable cover or cable tray where cables are in traffic locations. Never walk on hoses or cables
or move heavy objects over them. Route hoses and cables away from areas that expose them to possible
damage.

Provide proper hydraulic fluid filtration

For hydraulic systems equipped with a non-MTS hydraulic power unit, make sure that hydraulic fluid
filtration is established to maintain fluid cleanliness standards as stated in the Hydraulic Fluid Care Manual

Triaxial Cell Product Information | 17

Safety

(see the System Documentation CD). Particles present in the hydraulic fluid can cause erratic or poor
system response.

Protect accumulators from moving objects

For systems equipped with accumulators, protect accumulators with supports or guards. Do not strike
accumulators with moving objects. This could cause the accumulator(s) to separate from the manifold
resulting in equipment damage and personal injury.

Record changes

If you change any operating procedure, write the change and the date of the change in the appropriate
manual.

Provide test area guards

Use protective guards such as cages, enclosures, and special laboratory layouts when you work with
hazardous test specimens (for example, brittle or fragmenting materials or materials that are internally
pressurized).

Do not exceed the Maximum Supply Pressure

For hydraulic systems and components, make sure that hydraulic supply pressure is limited to the maximum
pressure defined by the system operating limits. Read and review “System Operating Limits” for the system.

Do not disable safety devices

Your system may have active or passive safety devices installed to prevent system operation if the device
indicates an unsafe condition. Do not disable such devices as it may result in unexpected system motion.

Use appropriately sized fuses

Whenever you replace fuses for the system or supply, ensure that you use a fuse that is appropriately
sized and correctly installed. Undersized or oversized fuses can result in cables that overheat and fuses
that explode. Either instance creates a fire hazard.

Provide adequate lighting

Ensure adequate lighting to minimize the chance of operation errors, equipment damage, and personal
injury.

Provide adequate ventilation

Make sure work and maintenance areas are adequately ventilated to minimize the risks associated with
the collection of hazardous fumes (such as vaporized hydraulic fluid). This is of special concern in confined
areas where hydraulic equipment is operating at high pressure in confined areas.

Provide means to access out-of-reach components

Make sure you can access system components that might be out of reach while standing on the floor. For
example, ladders or scaffolding might be required to reach load cell connectors on tall load units.

18 | Triaxial Cell Product Information

Safety

Safety Practices While Operating the System

Wear appropriate personal protection

Wear eye protection when you work with high-pressure hydraulic fluid, high-pressure air pressure, breakable
specimens, or when anything characteristic to the specimen could break apart.

Wear ear protection when you work near electric motors, pumps, or other devices that generate high noise
levels. This system may create sound pressure levels that exceed 70 dbA during operation.

Wear appropriate protection (gloves, boots, suits, respirators) whenever you work with fluids, chemicals,
or powders that may irritate or harm the skin, respiratory system, or eyes.

Provide test area enclosures

Use protective enclosures such as cages or shields, and special laboratory layouts when you work with
hazardous test specimens (for example, brittle or fragmenting materials or materials that are internally
pressurized).

You must evaluate risks due to ejected parts or materials from the test specimens. If the MTS Test Area
Enclosure option is not purchased by the customer, then for protection against ejected parts or materials
from test specimens and to control access to the machinery, the Customer must provide a Test Area
Enclosure to protect personnel.

Specimen temperature changes

During cyclic testing, the specimen temperature can become hot enough to cause burns. Wear personal
protection equipment (gloves) when handling specimens.

Handle chemicals safely

Whenever you use or handle chemicals (for example, hydraulic fluid, batteries, contaminated parts, electrical
fluids, and maintenance waste), see the appropriate MSDS documentation for that material and determine
the appropriate measures and equipment required to handle and use the chemical safely. Ensure that the
chemical is disposed of appropriately.

Know servohydraulic system interlocks

Interlock devices should always be used and properly adjusted. Interlock devices are designed to minimize
the chance of accidental damage to the test specimen or the equipment. Test all interlock devices for
proper operation immediately before a test. Do not disable or bypass any interlock devices as doing so
could allow hydraulic pressure to be applied regardless of the true interlock condition. The Reset/Override
button is a software function that can be used to temporarily override an interlock while attempting to start
the hydraulic power unit and gain control of the system.

Know system limits

Never rely on system limits such as mechanical limits or software limits to protect you or any personnel.
System limits are designed to minimize the chance of accidental damage to test specimens or to equipment.
Test all limits for proper operation immediately before a test. Always use these limits and adjust them
properly.

Triaxial Cell Product Information | 19

Safety

Do not disturb sensors

Do not bump, wiggle, adjust, disconnect, or otherwise disturb a sensor (such as an accelerometer or
extensometer) or its connecting cable when hydraulic pressure is applied.

Ensure secure cables

Ensure that all cable connections (electrical supply, control, feedback, sensor, communications, and so
forth) are either locking type, or are secured, to ensure that they cannot be disconnected by a simple act.
Do not change any cable connections when electrical power or hydraulic pressure is applied. If you attempt
to change a cable connection while the system is in operation, an open control loop condition can result.
An open control loop condition can cause a rapid, unexpected system response which can result in severe
personal injury, death, or damage to equipment. Also, ensure that all cables are connected after you make
any changes in the system configuration.

Stay alert

Avoid long periods of work without adequate rest. In addition, avoid long periods of repetitious, unvarying,
or monotonous work because these conditions can contribute to accidents and hazardous situations. If
you are too familiar with the work environment, it is easy to overlook potential hazards that exist in that
environment.

Contain small leaks

Do not use your fingers or hands to stop small leaks in hydraulic or pneumatic hoses. Substantial pressures
can build up, especially if the hole is small. These high pressures may cause the oil or gas to penetrate
your skin, causing painful and dangerously infected wounds. Turn off the hydraulic supply and allow the
hydraulic pressure to dissipate before you remove and replace the hose or any pressurized component.

Stay clear of moving equipment/avoid crush points

Stay clear of mechanical linkages, connecting cables, and hoses that move because you may get pinched,
crushed, tangled, or dragged along with the equipment. High forces generated by the system can pinch,
cut, or crush anything in the path of the equipment and cause serious injury. Stay clear of any potential
crush points. Most test systems can produce sudden, high-force motion. Never assume that your reactions
are fast enough to allow you to escape injury when a system fails.

Know the causes of unexpected actuator motions

The high force and velocity capabilities of MTS actuators can be destructive and dangerous (especially if
actuator motion is unexpected). The most likely causes of unexpected actuator response are operator
error and equipment failure due to damage or abuse (such as broken, cut, or crushed cables and hoses;
shorted wires; overstressed feedback devices; and damaged components within the servocontrol loop).
Eliminate any condition that could cause unexpected actuator motion.

Do not use RF transmitters

Keep radio frequency (RF) transmitters away from the workstation computers, remote terminals, and
electronics consoles. Intense RF fields can cause erratic operation of the more sensitive circuits in the
system.

20 | Triaxial Cell Product Information

Hazard Labels

Safety

DescriptionIcon

Failure to follow operating instructions can cause
death or serious injury.

Read and understand the operator’s manual before
using this machine.

Extreme heat hazard. Wear personal protective
equipment when working in hot areas or with hot
objects. For example, gloves.

Part Number: 572300-23

Hand crush or pinch point hazard. Stay alert and be
aware of possible moving parts. It is recommended
to keep clear of areas noted with this icon.

Part Number: 572300-36

Triaxial Cell Product Information | 21

Safety

DescriptionIcon

High pressure fluid can penetrate skin. Do not
tamper with fittings or hoses. Wear appropriate
protection such as safety goggles and gloves.
Maintain safe pressure levels.

Part Number: 572300-45

Crunch Zones and Pinch Points

Be aware of crush and pinch points on your system and keep personnel and equipment clear of these
areas during system operation. Pay attention to all hazard labels on the system. The following figure shows
the side and front view with crush zones and pinch points highlighted.

22 | Triaxial Cell Product Information

Introduction

Topics:

•

Introduction........................................................................................................................................24

•

Description.........................................................................................................................................24

•

Triaxial Cell Specifications.................................................................................................................32

Triaxial Cell Product Information | 23

Introduction

Introduction

About Series 656 Triaxial Cells

This manual documents the Model 656.04, Model 656.05, and Model 656.06 Triaxial Cells.

The Series 656 Triaxial Cells can be configured to perform compression, extension, and pore pressure
tests on geologic specimens.

These Triaxial Cells install in an MTS Series 315 Load Unit.

The Series 315 Load Unit applies high axial loads—up to 1000 kip (4600 kN) to the specimen.

About Pressure Intensifiers

The Pressure Intensifiers are designed to provide a source of fluid at pressures suitable for use in applying
pressure in a triaxial cell.

The Confining Pressure Intensifier is used to fill the triaxial cell with confining fluid, pressurize the fluid,
control the pressure, and empty the fluid from the triaxial cell at the conclusion of a test. An MTS Model

286.20 Confining Pressure Intensifier fills the Triaxial Cell with highly pressurized—up to 20,000 psi (140
MPa)—confining fluid. This fluid—usually a mineral oil—is applied to the entire specimen. We recommend
Multitherm®PG-1, a highly refined, clear, and non-toxic mineral oil.

When pore pressure tests are run, the Pore Pressure Intensifier is used to fill the specimen’s pores with
pore fluid, pressurize the fluid, and control the pressure. An MTS Model 286.30 Pore Pressure Intensifier
applies fluid—usually water—to the ends of the specimen. This fluid is also highly pressurized—up to
20,000 psi (140 MPa).

Together the confining pressure, pore pressure, and Load Unit’s axial load simulate the forces experienced
by the specimen when it is underground. The name “Triaxial Cell” comes from this Cell’s ability to reproduce
these three forces, although the specimen’s stress state is not strictly triaxial.

For more information about pressure intensifiers, see the appropriate manual.

• Model 286.20 Confining Pressure Intensifier Product Information manual, part number 015-020-201

• Model 286.30 Pore Pressure Intensifier Product Information manual, part number 015-022-701

Description

The Triaxial Cell has two major parts—the platen assembly and the bell. The platen assembly attaches to
the Load Unit’s actuator. The bell closes on the platen assembly to seal the Triaxial Cell.

The lift cylinders raise and lower the bell. The bell up and bell down controls operate the lift cylinders.
Once up, the bell can be locked in place using the T-locks.

The bell lift control has two modes. UseSetup mode to raise and lift the bell, and Run mode during a test.

Pressing the Emergency Stop button immediately shuts off system hydraulic pressure.

24 | Triaxial Cell Product Information

Introduction

The Lexan®door helps protect you against flying fragments. The interlock will interrupt the test controller
program any time the door is opened.

Optional external heater bands let you raise the temperature of the Triaxial Cell.

The carriage and track allow the entire Triaxial Cell, once disconnected from the Load Unit, to be rolled
out of the test area. This frees the Load Unit to run other kinds of tests.

Triaxial Cell On Load Frame

DescriptionItem

Front ViewA

Side View with Triaxial Cell Rolled Out on RailsB

Hoist Rings1

Lift Cylinder2

Hazard and Caution Labels (multiple locations)3

Lift Cylinder Control4

Controller Handset5

Triaxial Cell Product Information | 25

Introduction

DescriptionItem

Emergency Stop (E-Stop)6

Platen Assembly7

Sealing Cap Screws8

Bell9

Lexan Door10

Mounting Plate11

Spacer and Baseplate12

Rails13

Lexan Door Latches14

26 | Triaxial Cell Product Information