MTS Systems 318 Series User manual

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Model 318.10
Model 318.25
Model 318.50
318 Load Unit
Product Information
100-183-837 B

Copyright information © 2007, 2009 MTS Systems Corporation. All rights reserved.
Trademark information MTS is a registered trademark of MTS Systems Corporation within the United
States. This trademark may be protected in other countries.
Molykote is a registered trademark of Dow Chemical Corporation. All other
trademarks or service marks are property of their respective owners.
Publication information MANUAL PART NUMBER PUBLICATION DATE
100-183-837 A June 2007
100-183-837 B April 2009

318 Load Unit Contents 3
Contents
Technical Support 7
How to Get Technical Support 7
Before You Contact MTS 7
If You Contact MTS by Phone 9
Problem Submittal Form in MTS Manuals 10
Preface 11
Before You Begin 11
Conventions 12
Documentation Conventions 12
Introduction 15
Load Unit: Overview 15
318 Load Unit: Component Identification 17
318 Load Unit: Component Description 18
318 Load Unit: Specifications 20
Series 661 Force Transducer: Specifications 24
318 Load Unit: Dimensions 26
Safety 33
General Safety Practices 33
Safety Practices Before System Operation 34
Safety Practices While the System Is in Operation 39
Hazard Icons 41
318 Load Unit: Hazard Labels 42
45
318 Load Unit: Crush Point Hazards 45

318 Load Unit
4Contents
Installation 47
318 Load Unit: Unpack Upright Configuration 47
318 Load Unit: Unpack Horizontal Configuration 49
318 Load Unit: Connect Cables 54
318 Load Unit: Connect Hydraulics 56
318 Load Unit: Unlock the Crosshead 56
Operation 59
Load Unit: Operation Preface 59
318 Load Unit: Control Module 60
318 Load Unit: Crush Point Hazards 62
318 Load Unit: Specimen Installation 62
318 Load Unit: Position the Crosshead Hydraulically 65
318 Load Unit: Position the Crosshead Manually 66
318 Load Unit: Adjust the Grips’ Clamp Rate 69
318 Load Unit: Adjust the Grips’ Clamp Force 70
Maintenance 73
Routine Maintenance Overview Checklist 74
318 Load Unit: Maintenance Intervals 77
318 Load Unit: Daily Inspections 78
318 Load Unit: Clean the Columns 78
318 Load Unit: Prevent Rust 79
318 Load Unit: Maintain Airmount Pressures 80
318 Load Unit: Bleed the Hydraulic Lift Cylinders 81
318 Load Unit: Adjust the Hydraulic Locks 83
318 Load Unit: Lubricate the Crosshead Locking Bolts 86
318 Load Unit: Align the Force Transducer 87
111 Accumulator: Maintenance Overview 93
111 Accumulator: Check and Change Precharge Pressure 94
244 Actuator: Maintenance 98
298 HSM: Maintenance 98
252 Servovalve: Maintenance Overview 100
252 Servovalve: Replace the Filter Element 100
252 Servovalve: Adjust the Mechanical Null 102
Servohydraulic Load Frame Maintenance and Service Logs 107

318 Load Unit Contents 5
8 Hours/Daily 108
40 Hours/Weekly 109
80 Hours/Biweekly 110
500 Hours: Crosshead and Frame 111
500 Hours: Actuator 112
500 Hours: HSM 113
500 Hours: Hoses and Cables 114
500 Hours: Overall Complete System 115
500 Hours: Grips 116
1000 Hours 117
2000 Hours: Annual Maintenance 118

318 Load Unit
6Contents

318 Load Unit Technical Support 7
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 MTS software, look
for online help and README files that contain additional product information.
If you cannot find answers to your technical questions from these sources, you
can use the internet, e-mail, telephone, or fax to contact MTS for assistance.
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 MTS in one of the
following ways.
MTS web site
www.mts.com
The MTS web site gives you access to our technical support staff by means of a
Technical Support link:
www.mts.com > Contact MTS > Service & Technical Support
E-mail [email protected]
Telephone MTS Call Center 800-328-2255
Weekdays 7:00 A.M. to 5:00 P.M., Central Time
Fax [phone]
Please include “Technical Support” in the subject line.
Technical support
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 MTS > (choose your region in the right-hand
column) > (choose the location closest to you)
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 (material testing, simulation, and so forth). The number is usually written on
a label on your MTS equipment before the system leaves MTS. If you do not
have or do not know your MTS site number, contact your MTS sales engineer.
Example site number: 571167
When you have more than one MTS system, the system job number identifies
which system you are calling about. You can find your job number in the papers
sent to you when you ordered your system.
Example system number: US1.42460

318 Load Unit
8Technical Support
Know information from
prior technical
assistance
If you have contacted MTS about this problem before, we can recall your file.
You will need to tell us the:
•MTS notification number
•Name of the person who helped you
Identify the problem Describe the problem you are experiencing and know the answers to the
following questions:
•How long and how often has the problem been occurring?
•Can you reproduce the problem?
•Were any hardware or software changes made to the system before the
problem started?
•What are the model numbers of the suspect equipment?
•What model controller are you using (if applicable)?
•What test configuration are you using?
Know relevant
computer information
If you are experiencing 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 in which 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 is displayed briefly
when you launch the application, and can typically be found in the “About”
selection in the “Help” menu.
•It is also helpful if the names of other non-MTS applications that are
running on your computer, such as anti-virus software, screen savers,
keyboard enhancers, print spoolers, and so forth are known and available.

318 Load Unit Technical Support 9
If You Contact MTS by Phone
Your call will be registered by a Call Center agent if you are calling within the
United States or Canada. Before connecting you with a technical support
specialist, the agent will ask you for your site number, name, company, company
address, and the phone number where you can normally be reached.
If you are calling about an issue that has already been assigned a notification
number, please provide that number. You will be assigned a unique notification
number about any new issue.
Identify system type To assist the Call Center agent with connecting you to the most qualified
technical support specialist available, identify your system as one of the
following types:
•Electromechanical materials test system
•Hydromechanical materials test system
•Vehicle test system
•Vehicle component test system
•Aero test system
Be prepared to
troubleshoot
Prepare yourself for troubleshooting while on the phone:
•Call from a telephone when you are close to the system so that you can try
implementing 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
Prepare yourself in case we need to call you back:
•Remember to ask for the notification number.
•Record the name of the person who helped you.
•Write down any specific instructions to be followed, such as data recording
or performance monitoring.
After you call MTS logs and tracks all calls to ensure that you receive assistance and that action
is taken regarding your problem or request. If you have questions about the status
of your problem or have additional information to report, please contact MTS
again and provide your original notification number.

318 Load Unit
10 Technical Support
Problem Submittal Form in MTS Manuals
Use the Problem Submittal Form to communicate problems you are experiencing
with your MTS software, hardware, manuals, or service which have not been
resolved to your satisfaction through the technical support process. This 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.
The Problem Submittal Form can be accessed:
•In the back of many MTS manuals (postage paid form to be mailed to MTS)
•www.mts.com > Contact Us > Problem Submittal Form (electronic form to
be e-mailed to MTS)

318 Load Unit Preface 11
Preface
Before You Begin
Safety first! Before you attempt to use your MTS product or system, read and understand the
Safety manual and any other safety information provided with your system.
Improper installation, operation, or maintenance of MTS equipment in your test
facility can result in hazardous conditions that can cause severe personal injury or
death and 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 MTS manuals in paper or
electronic form.
If you have purchased a test system, it may include an MTS System
Documentation CD. This CD contains an electronic copy of the MTS manuals
that pertain to your test system, including hydraulic and mechanical component
manuals, assembly drawings and parts lists, and operation and preventive
maintenance manuals. Controller and application software manuals are typically
included on the software CD distribution disc(s).

318 Load Unit
12
Conventions
Preface
Conventions
Documentation Conventions
The following paragraphs describe some of the conventions that are used in your
MTS manuals.
Hazard conventions As necessary, hazard notices may be embedded in this manual. These notices
contain safety information that is specific to the task 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 the directions that are given.
Three different levels of hazard notices may appear in your manuals. Following
are examples of all three levels.
Note For general safety information, see the safety information provided with
your system.
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.
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 notices indicate the presence of a hazard with a low level of risk which,
if ignored, could cause moderate or minor personal injury, equipment damage, or
endanger test integrity.
Notes Notes provide additional information about operating your system or highlight
easily overlooked items. For example:
Note Resources that are put back on the hardware lists show up at the end of
the list.
Special terms The first occurrence of special terms is shown in italics.
Illustrations Illustrations appear in this manual to clarify text. It is important for you to be
aware that these illustrations are examples only and do not necessarily represent
your actual system configuration, test application, or software.
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.
DANGER
WARNING
CAUTION

Conventions
318 Load Unit Preface 13
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.

318 Load Unit
14
Conventions
Preface

318 Load Unit Introduction 15
Introduction
Load Unit: Overview
The Load Unit is the primary structure for most materials testing. It is a stand-
alone testing unit. The load unit consists of the load frame plus additional parts,
such as hydraulic crosshead lifts and control modules. Load units come in
different sizes and shapes. The following illustration shows typical load units
with common accessories.
The Load Units are designed for testing materials. They can perform tension and
compression tests, fatigue and fracture mechanics tests, as well as other tests.
MTS manufactures a variety of grips, mounting fixtures, test area guards, and
environmental chambers that can be used with the load unit.
Model 318 Model 322 Model 359
Typical Load Units

318 Load Unit
16 Introduction
What you
need to know
MTS Systems Corporation assumes that you know how to use your controller.
See the appropriate manual for information about performing any controller-
related step in this manual’s procedures. You are expected to know how to
perform the following procedures:
•Turn hydraulic pressure on and off
•Select a control mode
•Adjust the actuator position
•Zero a sensor signal
•Zero a sensor output
•Use your grips and fixtures
•Define a simple test
•Run a test

318 Load Unit Introduction 17
318 Load Unit: Component Identification
Component Descriptions
ITEM COMPONENT DESCRIPTION
1 Crosshead Moves the up and down the column to accommodate different sized
specimens and fixtures. The crosshead is stiff and light weight; it is one end of
the force train.
2 Crosshead locks Clamps the crosshead to the columns. The locks are hydraulically powered.
3 Crosshead lifts Raises and lowers the crosshead hydraulically to accommodate different
specimen sizes. The lifts are small hydraulic actuators.
11
1
12
2
8
5
7
9
10
3
6
4

318 Load Unit
18 Introduction
318 Load Unit: Component Description
The load unit is a stand alone testing structure. It consists of the following
components:
•Load frame
•Crosshead lifts and locks
•Manifold
–Actuators
– Servovalves
– Accumulators
•Transducers
•Grip controls
4 Control panel
Grip
controls
Crosshea
d lift
control
Emergenc
y Stop
The Emergency Stop button is standard; the other controls are optional.
Clamps and unclamps the hydraulically controlled grips during specimen
installation and removal.
Controls the crosshead lifts to raise and lower the crosshead hydraulically.
Removes hydraulic pressure from the load unit and issues an interlock signal
to the controller to stop the test program.
5 Servovalve Controls both the flow rate and the direction of fluid entering the actuators. It
determines how fast the actuator extends or retracts.
6Isolationpads
Dampens the natural frequency to about 20 Hz. Optional air inflated isolators
dampen the frequency to about 2 Hz.
7 Accumulators Stores hydraulic fluid under pressure to increase the actuator’s response time.
One accumulator connects to the pressure line; the other to the return line.
8LVDT Measures the displacement of the actuator’s travel. The linear variable
displacement transducer (LVDT) is located inside the actuator.
9Manifold Serves as the junction point between the hydraulic power unit (HPU),
accumulators, servovalve, and actuator. The actuator manifold controls the
hydraulic circuit that connects the hydraulic components.
10 Linear actuator Applies axial forces to specimens. The actuator is a hydraulically powered
device that provides linear displacement of (or forces into) a specimen. Grips
and fixtures can be mounted to the actuator.
11 Force transducer Measures the axial forces applied to specimen.
12 Lifting rings Allows the load unit to be moved by lifting the entire load unit.
Component Descriptions
ITEM COMPONENT DESCRIPTION

318 Load Unit Introduction 19
Load frame The load frame is the basic structure which provides the reaction mass for the
force train. The base of the load frame is one end of the reaction mass and the
crosshead is the other end of the reaction mass. Installing a specimen and other
fixtures or components between the load unit base and the crosshead create a
force train.
The load frame and the other hydraulic components mounted to it collectively
create the load unit. The base houses the actuators, servovalves, and hydraulic
manifold. The crosshead is mounted above the base by two columns. A control
panel lets you operate the crosshead lifts, locks, and grips to assist in specimen
installation procedures.
Crosshead lifts
and locks
The crosshead can be positioned anywhere along the load frame columns. It is
moved along the column with hydraulic lifts. When the crosshead is in an
appropriate test position, it is hydraulically clamped to that position. This lets
you change the load unit to test specimens of different lengths.
Actuator manifold The Series 298 Actuator Manifold (also called a hydraulic service manifold or
HSM) acts as the hydraulic interface between the HPU and the components
mounted to the manifold (actuator, servovalves, and accumulators) of the load
unit. It contains the required hydraulic porting and plumbing to accommodate the
hydraulic components. The manifold can also control the hydraulic pressure to
the load unit.
Actuators The Series 244 Actuators can be located in the middle of the load unit base or
crosshead. It is a hydraulically powered piston that applies displacement of (or
force into) a specimen. It can apply equal power in tension and compression. One
end of the test specimen is installed into a fixture which is mounted to the end of
the actuator rod.
Servovalves The Series 252 Servovalves regulates the direction and flow of the hydraulic
fluid to and from a hydraulic actuator. The servovalve responds to the polarity
and magnitude of the command signal generated by the controller.
Accumulators The Series 111 Accumulators suppress line-pressure fluctuations. The load unit
includes a pressure-line accumulator to provide fluid storage so a constant line
pressure can be maintained at the servovalves for maximum performance. The
return-line accumulator minimizes return-line pressure fluctuations.
Pressure control The load unit can be configured for several pressure configurations. The free low
configuration passes the hydraulic pressure from the HPU (or hydraulic service
manifold) through the manifold to the hydraulic components. The hydraulic
pressure options include on/off control, high/low/off control, and high/low/off
control with a proportional valve to ramp the pressure transitions.
Transducers The load unit includes a force transducer and an LVDT.
Force The force transducer (also called load cell or force sensor) measures the amount
of tension or compression and rotational torque applied to it. It has four strain
gages that form a balanced Wheatstone bridge. When forces are applied to the
bridge, it becomes unbalanced and produces an electrical signal that is
proportional to the force applied to it. The force transducer is a resistive device
and requires a DC conditioner to process the axial signal from the Wheatstone
bridge.

318 Load Unit
20 Introduction
LVDT The LVDT measures the linear actuator’s travel. The LVDT consists of a
transformer with one primary and two secondary coils wound on a common
cylinder. The coil is stationary inside the actuator. A core is attached to the piston
rod of the actuator. As it moves inside the coil, it produces an electrical signal
that represents the position of the piston rod. The phase of the signal indicates the
direction the actuator rod is moving. An LVDT requires an AC conditioner to
process the signal.
Grip Controls The grip controls provide independent clamping control of the upper and lower
grips. The maximum pressure for the grip controls can be set up to 69 MPa
(10,000 psi). The pressure is factory set to 20 MPa (3000 psi); 45 MPa (6500
psi); or 69 MPa (10,000 psi) to accommodate a variety of grips manufactured by
MTS Systems Corporation. A front panel control allows the grip pressure to be
adjusted within the factory setting. A rate control sets how fast the grips open and
close.
318 Load Unit: Specifications
This section provides the specifications of the Series 318 Load Unit.
General specifications The following table lists general specifications for the Series 318 Load Unit:
PARAMETER SPECIFICATION
Load frame
Lifts
Locks
Grip control
Hydraulic (optional)
Hydraulic (optional)
Hydraulic (optional)
Service manifold
Maximum flow
Series 298 Actuator Manifold
114 L/min (30 gpm)
Axial actuator
Displacements
Series 244 Actuator
100 mm (4 in)
150 mm (6 in)
250 mm (10 in)
Accumulator Series 111 Accumulator