MTS Material Test System Operation 100-196-370 D be certain. © 2013 MTS Systems Corporation. All rights reserved. MTS, TestStar, and TestWare registered trademarks of MTS Systems Corporation within the United States. These trademarks may be protected in other countries. All other trademarks or service marks are property of their respective owners. Contents 1.0 Preface 5 1.1.0 Before You Begin............................................................................................................................6 1.2.0 Documentation Conventions...........................................................................................................6 2.0 Technical Support 9 2.1.0 How to Get Technical Support......................................................................................................10 2.2.0 Before You Contact MTS..............................................................................................................10 2.3.0 If You Contact MTS by Phone......................................................................................................12 2.4.0 Problem Submittal Form in MTS Manuals...................................................................................13 3.0 Introduction 15 3.1.0 Manual Overview..........................................................................................................................16 3.2.0 Typical Test System Configuration...............................................................................................16 3.2.1.0 Load Frame Test Controller...........................................................................................20 3.2.2.0 Servohydraulic and Mechanical Components................................................................21 3.3.0 System Control Theory.................................................................................................................22 3.4.0 Interlocks.......................................................................................................................................24 4.0 Safety 25 4.1.0 Overview.......................................................................................................................................26 4.1.1.0 Safety Information Overview.........................................................................................26 4.1.2.0 Hazard Placard Placement..............................................................................................26 4.2.0 Safety Practices.............................................................................................................................27 4.2.1.0 General Safety Practices.................................................................................................27 4.2.2.0 Safety Practices Before Operating the System...............................................................27 4.2.3.0 Safety Practices While Operating the System ...............................................................31 5.0 Installation Guidelines 35 5.1.0 Installation Guidelines...................................................................................................................36 5.2.0 Facility Preparation.......................................................................................................................36 5.3.0 Electrical Power Distribution........................................................................................................38 5.4.0 Grounding Requirements..............................................................................................................39 5.5.0 Test Controller and Console Requirements...................................................................................39 5.6.0 Cooling Water Requirements........................................................................................................40 MTS Material Test System Operation 3 5.7.0 Connecting the System Components.............................................................................................40 5.8.0 System Startup...............................................................................................................................41 6.0 Getting Started 43 6.1.0 Overview.......................................................................................................................................44 6.2.0 Define the Test Configuration.......................................................................................................44 6.2.1.0 Load Unit Setup.............................................................................................................44 6.2.2.0 Select and Set Up the Data Acquisition Equipment.......................................................45 6.2.3.0 Set Up the Counter.........................................................................................................45 6.2.4.0 Set Up the Underpeak Detector......................................................................................45 6.3.0 Define the Test Parameters............................................................................................................46 6.3.1.0 Select Appropriate Range...............................................................................................46 6.3.2.0 Define Test Program.......................................................................................................46 6.3.3.0 Calculate Error Detection Level.....................................................................................47 6.3.4.0 Calculate Upper and Lower Limit Detector Levels.......................................................48 6.3.5.0 Calculate Underpeak Detector Levels............................................................................50 6.4.0 Select Test Setup Methods............................................................................................................52 6.4.1.0 Servo Loop Adjustments................................................................................................52 6.5.0 Determine the Crosshead Position................................................................................................55 7.0 Operation 57 7.1.0 Operation Overview......................................................................................................................58 7.2.0 Initial Setup...................................................................................................................................58 7.3.0 Set Detector Levels.......................................................................................................................59 7.4.0 Adjust Displacement Servo Loop (optional).................................................................................60 7.5.0 Install the Specimen......................................................................................................................61 7.5.1.0 Specimen Installation with Model 370 Load Frame......................................................61 7.5.2.0 Specimen Installation with 318, 331, and 359 Load Frames.........................................63 7.6.0 Adjust Load Servo Loop...............................................................................................................65 7.7.0 Set Up the Program, Detectors, Counter, and Data Acquisition...................................................67 7.8.0 Run the Test...................................................................................................................................68 8.0 Routine Maintenance 69 8.1.0 Maintenance Overview..................................................................................................................70 9.0 Decommission 75 9.1.0 Decommission Test System...........................................................................................................76 4 MTS Material Test System Operation 1.0 Preface Topics: • • Before You Begin.....................................................................................................................................6 Documentation Conventions....................................................................................................................6 MTS Material Test System Operation 5 1.0 Preface 1.1.0 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). 1.2.0 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. 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. 6 MTS Material Test System Operation 1.0 Preface 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. Example: 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. 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. MTS Material Test System Operation 7 2.0 Technical Support Topics: • • • • How to Get Technical Support...............................................................................................................10 Before You Contact MTS.......................................................................................................................10 If You Contact MTS by Phone...............................................................................................................12 Problem Submittal Form in MTS Manuals.............................................................................................13 MTS Material Test System Operation 9 2.0 Technical Support 2.1.0 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 www.mts.com > Contact Us (upper-right corner) > In the Subject field, choose To escalate a problem; Problem Submittal Form E-mail Worldwide: tech.support@mts.com Europe: techsupport.europe@mts.com Telephone Worldwide: 1 800 328 2255 - toll free in U.S.; +1 952 937 4000 - outside U.S. Europe: +800 81002 222, International toll free in Europe 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 2.2.0 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 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 10 MTS Material Test System Operation 2.0 Technical Support 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 • Messaging applications MTS Material Test System Operation 11 2.0 Technical Support 2.3.0 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. • Write down any specific instructions. 12 MTS Material Test System Operation 2.0 Technical Support 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. 2.4.0 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 MTS Material Test System Operation 13 3.0 Introduction Topics: • • • • Manual Overview...................................................................................................................................16 Typical Test System Configuration.........................................................................................................16 System Control Theory..........................................................................................................................22 Interlocks................................................................................................................................................24 MTS Material Test System Operation 15 3.0 Introduction 3.1.0 Manual Overview This manual provides operating guidelines, installation guidelines, and safety practices for operation of an MTS Test System. This manuals deals primarily with the hardware components used to configure a typical MTS load frame based materials testing system: the load frame, the grips and fixtures used to secure the specimen during testing, and the MTS Hydraulic Power Unit. It also contains information on the MTS controller and a general description of the test system control theory. This manual does not contain information on the software used to create and run specific testing applications such as low cycle fatigue or monotonic tension. For this information, refer to your software manuals; for example TestSuite or TestWorks. An MTS test system can be designed for a wide variety of testing applications. To provide maximum flexibility for operation, the information in this manual is written for a typical system. In addition to studying this manual, MTS recommends you become acquainted with the system by reading the introductory sections of the product manuals. 3.2.0 Typical Test System Configuration An MTS Test System can be designed for a wide variety of testing applications. To provide maximum flexibility for operation, the information in this manual is written for the typical system that includes as a minimum configuration a test controller, load frame, and hydraulic power unit. The following illustrations show the common system components and uses the MTS Landmark load frame for illustration purposes. All MTS load frames have similar components. Some load frames will have a t-slot tables as a baseplate to accommodate various fixtures and actuator and column positioning. Figure 1: Test Controller and Components 16 MTS Material Test System Operation 3.0 Introduction Item Description 1 Test Controller Software (Typical) • 793 System Software • 793 Applications • 793 Utilities 2 Cables 3 Transducer ID Cable 4 Outlet Strip 5 Line Supply 6 MTS Documentation 7 PC Workstation 8 PC Link Figure 2: Hydraulic Power Unit Table 1: Hose connections to the HSM Item Description 1 Pressure 2 Return 3 Drain MTS Material Test System Operation 17 3.0 Introduction Figure 3: Hydraulic Service Manifold Table 2: Hose connections from the HPU and to the actuators Item Description 1 Pressure 2 Return 3 Drain Figure 4: Load Frame Item Description 1 Servovalve 18 MTS Material Test System Operation 3.0 Introduction Item Description 2 Hydraulic service manifold 3 Hose connections: • Pressure • Return • Drain 4 Hand set (some models) 5 Actuator speed switch (some models) 6 E-Stop button 7 Hydraulic lift lock controls 8 Grip controls 9 Linear actuator 10 Load cell Additional testing accessories are also available. For information on optional accessories, refer to the individual product manuals. Figure 5: Testing Accessories MTS Material Test System Operation 19 3.0 Introduction Item Description 1 Environmental Accessories 1A. High temperature furnace 1B. Environmental chamber 1C. Temperature controller 2 Extensometers 3 Alignment accessories 3A. High temperature furnace 3B. Environmental chamber 4 Remote station control 5 Remote E-Stop (optional) 6 Test area guard 7 Grips and bend fixtures 3.2.1.0 Load Frame Test Controller The test controller can be either a FlexTest SE Basic, FlexTest SE Plus, FlexTest GT, or FlexTest 40/60/100/200. Note: Because the FlexTest 40 is the most common test controller used on the MTS Landmark System, this manual will primarily focus on that controller. The FlexTest 40, FlexTest SE Plus, and FlexTest SE 2-Channel are single station PC-based digital controllers. The FlexTest 60/100/200 controllers are PC-based multi-station digital controllers. In more complex testing situations, the multi-station controller controls many channels on a number of independent stations; with one or more of the stations being a load frame based test system. These test controllers consist of: • A PC running Series 793 Software (except the FlexTest SE Basic). • A chassis equipped with Series 493 or Series 494 electronics. • A handset for load frame control during specimen loading and unloading. The handset is also used for setup and can initiate tests at the load frame. • The Station Manager application running on the PC as the primary test interface. • A software application (such as MultiPurpose TestWare) to provide the command and data acquisition functions of running a test. The FlexTest SE Basic is nonautomated and operates from the front panel controls. 20 MTS Material Test System Operation 3.0 Introduction 3.2.2.0 Servohydraulic and Mechanical Components The following paragraphs briefly describe the servohydraulic and mechanical components that are typical supplied with the MTS Landmark System. Load frame There are a variety of load frames that can be supplied with the system. The load frame is the mechanical foundation of the test system in which the load cell transducer, specimen fixturing or grips, and hydraulic actuator are mounted. The load frame can be configured with hydraulic-controlled crosshead locks and lifts that allow convenient crosshead positioning during specimen installation. (Manual crosshead locks and lifts and manual crosshead locks and hydraulic lifts are also available on some models.) Load frames come in a variety of configurations, but all have the same basic components described below. Some examples are: • Basic two-column floor-standing frames for general material testing such as the MTS Landmark Load Frame • Table-top frames for biomechanical and biomaterials testing such as the MTS Bionix Load Frame • T-slot baseplate frames for general component testing such as the MTS Model 322 Load Frame • Frames specifically designed for high cycle elastomer testing such as the MTS Model 331.02 and 331.05 Load Frames. • Frames with high mass base designs for shock absorber testing such as the MTS Model 84X and 85x Load Frames Hydraulic actuator The hydraulic actuator is typically mounted in the base of the load frame; some load frames can have crosshead mounted actuators. It is the force-generating and/or positioning device in the system. Hydraulic fluid is applied to either side of the actuator's piston to cause its piston rod to extend or retract. Servovalve(s) The servovalve converts a control signal (from the test controller) to control the direction and amount of fluid flow to the actuator. This regulated hydraulic fluid flow controls the displacement or force being applied to the test specimen. Hydraulic service manifold The hydraulic service manifold contains the required hydraulic porting to accommodate the servovalve(s), an actuator, and the crosshead lifts. The actuator and servovalve(s) are mounted to the manifold. The manifold includes a low hydraulic flow feature that lets you limit the velocity of the actuator for specimen installation. Accumulators The accumulators suppress line-pressure fluctuations. The pressure-line accumulators provide fluid storage so a constant line pressure can be maintained at the servovalve(s) for maximum performance. The return-line accumulator minimizes return-line pressure fluctuations. MTS Material Test System Operation 21 3.0 Introduction Hydraulic power supply The hydraulic power unit (HPU) provides pressurized hydraulic fluid to the servovalve. An HPU typically includes a reservoir for the hydraulic fluid, a pump to pressurize the hydraulic fluid, a motor to run the pump, a heat exchanger to cool the hydraulic fluid, and sensors to monitor the level, pressure, and temperature of the hydraulic fluid. Transducer(s) The load cell transducer, mounted underneath the load frame crosshead, is used to measure the polarity and magnitude of the force that is applied to the specimen. The extensometer is a sensor attached to a specimen that measures a dimensional change (gage length or strain) that occurs in the specimen while being tested. Extensometers use a Wheatstone bridge circuit to detect the dimensional changes. The LVDT (linear variable differential transformer) transducer is mounted inside the hydraulic actuator. The LVDT is used to measure the axial position (or displacement) of the actuator piston rod. Encoders are used in axial/torsional systems to measure rotation. Specimen fixtures or grips Either fixtures or grips are used to hold the specimen in alignment with the force train during the test. The force train is comprised of the servohydraulic and mechanical components which receive the forces applied by the hydraulic actuator. Environmental products Optional environmental products can be incorporated into the test system configuration. These include temperature chambers, furnaces, and associated temperature controllers. When using products to control specimen temperature, be sure to use other products (for example grips and extensometers) that can withstand the test temperatures. Test area enclosure MTS recommends the use of test area enclosures. Protective enclosures such as cages or shields should be used when you work with hazardous test specimens (for example, brittle or fragmenting materials or materials that are internally pressurized). If a test area enclosure is not purchased form MTS< it is the customer’s responsibility to ensure a safe working environment, 3.3.0 System Control Theory The test system uses a control technique referred to as “closed-loop control.” The theory of this control technique and the various control modes and interlock detection methods that can be used are described in the following subsections. Closed loop control In a test system, the test controller (for example the MTS FlexTest 40) provides closed-loop control of the system’s mechanical and hydraulic components. 22 MTS Material Test System Operation 3.0 Introduction Table 3: Simple Control diagram Item Description 1 Test command 2 Summing and conditioning 3 Station manager 4 Closed loop 5 Feedback source When reduced to its basic form, a Series 793 test system typically includes these elements. (The command can also be provided by a function generator or MultiPurpose TestWare). The configuration of the devices provides a means of comparing a command (programmer output) signal with a feedback (transducer output) signal to generate a signal that controls the servovalve. The servovalve controls hydraulic flow to the actuator which moves the actuator piston rod. The actuator piston rod applies the force required to load or displace the specimen being tested. The control method is referred to as “closed-loop control” because the process of command, feedback, comparison, and servovalve control is totally a function of the control circuitry and occurs without operator interaction. In closed-loop control, the programmer is used to generate the command signal. The controller provides the necessary circuitry for the comparison of the command signal and the feedback signal. The controller also contains the circuits that generate the servovalve control signal and condition the transducer output. Control modes Typical control modes that can be used to control the test include load, displacement, and strain. The control mode uses the controller's summing junction to compare the command signal and the conditioned feedback signal to produce a DC error signal. The polarity and magnitude of the DC error signal causes the valve driver circuit to produce a signal that opens the servovalve spool in a direction and by an amount necessary to allow fluid to flow into the actuator and cause the desired force, displacement, or strain. As the command and feedback change, the summing junction continuously generates a DC error signal that drives the servovalve to create the desired actuator response. MTS Material Test System Operation 23 3.0 Introduction 3.4.0 Interlocks The test controller incorporates interlock circuitry that can automatically stop a test when a system problem, specimen failure, or an operator error could result in unwanted or unexpected actuator movement. The test controller interlock circuitry will cause one of two interlocks to occur in response to specific conditions encountered during testing. These interlocks are: • Hydraulic Interlock – stops the program and removes hydraulic pressure from the system. • Program Interlock – stops the current test program when certain test parameters are not met or are exceeded. Because specimen installation procedures and testing situations can be adversely affected by the sudden loss of actuator pressure that accompanies a hydraulic interlock, the operator might choose to enable or disable the interlock detectors during system setup. Disabling the interlock detectors allow the operator to prevent a hydraulic shutdown if an interlock condition occurs. the following table lists the possible types of interlock conditions for the test controller. Table 4: Interlocks Condition Cause Type of Interlock Emergency Stop Emergency Stop or E-Stop button pressed Hydraulic Program Aux Open circuit at the Prog Intlk rear panel connector Program Hydraulic event Fault in the performance of hydraulic components Hydraulic Mechanical event Fault in the performance of mechanical components Hydraulic End-of Count Completion of a preset number of cycles in the current Hydraulic or Program test program Underpeak Selected signal fails to reach a preset minimum or maximum level Error 2 3 1 option When the control channel's DC error signal exceeds Hydraulic with indicator 2 a preset maximum level option Upper LimitLower Limit Transducer feedback signal exceeds a preset minimum or maximum level 1 Hydraulic with indicator Hydraulic with indicator 3 option These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to the test controller documentation. These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to the test controller documentation. These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to the test controller documentation. 24 MTS Material Test System Operation 4.0 Safety Topics: • • Overview................................................................................................................................................26 Safety Practices.....................................................................................................................................27 MTS Material Test System Operation 25 4.0 Safety 4.1.0 Overview 4.1.1.0 Safety Information Overview MTS systems are designed to generate single-axis or multi-axial motions and forces simultaneously in a controlled environment and impart these motions and forces into a specimen that is secured to the system. When you prepare to operate the system and during system operation, ensure the following: • Do not use or allow personnel to operate the system who are not experienced, trained, or educated in the inherent dangers associated with this system and who are not experienced, trained, or educated with regard to the intended operation as it applies to this system. • Do not disable safety components or features (including limit detectors, light curtains, or proximity switches/detectors). • Do not attempt to operate the system without appropriate personal safety gear (for example, hearing, head, hand, and eye protection). • Do not apply energy levels that exceed the maximum energies and velocities for the system design. Refer to the system specifications for these maximum values. • Do not use a specimen that does not meet the minimum (if applicable) or exceeds the maximum allowable mass. Refer to the system specifications for these values. • Do not use specimens that are combustible, flammable, pressurized, or explosive. • Do not use humans as specimens or allow humans to ride in or on the specimen or the system for any purpose unless the system is man-rated and all associated safety conditions are strictly enforced. • Do not modify the system or replace system components using parts that are not MTS component parts. • Do not effect repairs using parts or components that are not manufactured to MTS specifications. • Do not operate the system in an explosive atmosphere. • Do not use the system in an area where uncontrolled access to the system is allowed when the system is in operation. 4.1.2.0 Hazard Placard Placement Hazard placards contain specific safety information and are affixed directly to the system so they are plainly visible. Each placard describes a system-related hazard. When possible, international symbols (icons) are used to graphically indicate the type of hazard. The placard label indicates the severity of the hazard. In some instances, the placard may contain text that describes the hazard, the potential result if the hazard is ignored, and general instructions about how to avoid the hazard. Refer to the product information manuals for a description of hazard placards associated with the various products that comprise your system. 26 MTS Material Test System Operation 4.0 Safety 4.2.0 Safety Practices 4.2.1.0 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 user’s responsibility to take the machine out of service and contact MTS Service if discrepancies in system operation are found. 4.2.2.0 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. 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. MTS Material Test System Operation 27 4.0 Safety 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. 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. 28 MTS Material Test System Operation 4.0 Safety 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. • 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 MTS Material Test System Operation 29 4.0 Safety 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, refer to 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 (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. 30 MTS Material Test System Operation 4.0 Safety 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. 4.2.3.0 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). MTS Material Test System Operation 31 4.0 Safety Customer must evaluate risks due to ejected parts or materials from the test specimens. If the MTS Test Area Enclosure option is not selected 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), refer to 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. 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. 32 MTS Material Test System Operation 4.0 Safety 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. MTS Material Test System Operation 33 5.0 Installation Guidelines Topics: • • • • • • • • Installation Guidelines............................................................................................................................36 Facility Preparation................................................................................................................................36 Electrical Power Distribution..................................................................................................................38 Grounding Requirements.......................................................................................................................39 Test Controller and Console Requirements...........................................................................................39 Cooling Water Requirements.................................................................................................................40 Connecting the System Components....................................................................................................40 System Startup......................................................................................................................................41 MTS Material Test System Operation 35 5.0 Installation Guidelines 5.1.0 Installation Guidelines The MTS Test System is typically installed by qualified MTS field service engineers. This section provides reference information as it applies to a typical system configuration that might help you become more familiar with your system. The difference in test setup and laboratory layouts will influence the final layout of the testing system components. These and other customer specific requirements must be considered prior to system installation. 5.2.0 Facility Preparation To get the maximum intended use of the system, careful consideration should be given to planning its installation and the necessary support services required as part of the total system installation. This includes the types of testing that will be performed as well as the building facilities, contract services and support personnel that can be required during installation of the system. Each test application has its own requirements in addition to the test system requirements. Therefore, it is recommended that overall planning be considered before uncrating the system. To identify different installation considerations that are unique to the many setup configurations available with the system, read the following paragraphs thoroughly. Space requirements Consideration must be given to planning for the space requirements around the equipment to allow for specimen installation and the proper maintenance of the equipment. Additional space might also be required, during installation of the equipment, to facilitate moving the various system components into place. Consideration should also be given to handling components, storage of test data, and storage of fixturing and the associated tools necessary for use and service of the system. If hazardous test components (such as fragmentizing materials or internally pressurized materials) are used in the test, protective enclosures and special laboratory layouts are recommended. When the final layout for the test area has been designed, the dimensional and weight information (located in the specification tables found in the various product manuals) should be supplied to the building facility personnel to ensure that proper building loading and vibration considerations have been evaluated. Limit facility access Care should be taken to restrict access to the testing area. This will minimize the hazards to bystanders or unauthorized personnel by preventing access to the test area where highly destructive forces are common. Handling fixtures and components Movement of fixtures or components into and out of the test area must be considered early in the planning of the site layout. With smaller components, the use of a rolling work cart with lift-off storage drawers is recommended to ease the handling of components and to minimize the chance of damage to the components prior to and after the test. As component size and fixturing increase beyond the typical lifting capacity of 36 MTS Material Test System Operation 5.0 Installation Guidelines laboratory personnel, use of an overhead crane, lifting straps or a forklift might be necessary to handle components or fixtures. Heat dissipation To provide adequate heating and air conditioning to the test area for comfortable working conditions and proper operation of the equipment, the heat dissipation of the hydraulic power equipment, electronics console and other equipment must be considered. Heat dissipation for the console and other electronic units can be estimated by summing the heat loss from the equipment, personnel, and other heat sources such as furnaces. Add 20% additional heat gain to this figure to allow for future changes in test requirements. The hydraulic power Unit (HPU) is normally located in a room separate from the test system to reduce heat and acoustical noise near personnel. Heat dissipation from the HPU is typically about 10% of the motor horsepower. This heat dissipation is typically compensated for by providing exterior ventilation or cooling. A 40°C (104°F) maximum environment is recommended for the HPU. For specific HPU requirements, refer to the atmospheric heat and noise rating specifications located in the specification tables found in the HPU product manual. Altitude Operating a system at high altitudes can present additional heat dissipation problems. This type of problem can require the use of an air-conditioned environment or cooling fans to reduce the heat load. The maximum allowable operating temperature should be reduced by 1.8°C for each 1000 meters (1°F for each 3280 feet) above sea level. The maximum altitude for non-sealed flying-head disk drive systems is normally 2450 meters (8000 feet). Check the drive manufacturer's product specifications. Temperature Room air heating and cooling outlets should be directed so that they spread air uniformly throughout the room. This will help to prevent changes in specimen characteristics and test data associated with varying temperatures. The operating temperature range of the electronic equipment is 10-50°C (50-122°F). This includes most temperature-sensitive equipment, such as disk drives, which are dependent on cooler air to maintain the proper height of their read/write heads. The operating temperature range of the HPU is 10-40°C (50-104°F). Care must be taken to ensure that it is not placed in a location subject to freezing when water cooling is used. Reservoir heaters and oil-to-air coolers are available from MTS. Relative humidity The recommended control for relative humidity in the test room is a range of 10-85% (non-condensing). The risk of static discharge, which easily damages logic components and causes loss of data in memory devices, is increased by low humidity. Excessive humidity can result in electrical leakage currents or component failure. Acoustics Some types of testing can produce excessive noise that can cause hearing loss.The use of hearing protection is recommended for personnel involved in long-term testing in a noisy testing environment. Acoustical treatment of walls and ceiling might be necessary to prevent harm to personnel. If disk drives are included in the system, acoustical materials used should not be of a type that generates or collects dust. In MTS Material Test System Operation 37 5.0 Installation Guidelines addition, it is recommended that the hydraulic power unit be located in a room separate from the test system, if possible, to reduce noise in the test area. Mechanical shock/vibration In testing situations where impact testing is performed or in higher speed fatigue testing, cyclic loads and simple shock pulses can be introduced into the laboratory floor. Adequate isolation is often possible with vibration isolators. However, in some cases, an air bag isolation device might be required. Contact an MTS representative for additional information. Radiated emissions Operation of the system can be affected by sources of electromagnetic interference (EMI) that are near the system controls, computer, and related peripheral equipment. Common sources of EMI are thunderstorms, broadcast systems, high voltage power lines, power tools, mobile communications, radar, vehicle ignition systems, static electricity, induction heaters, and fluorescent lights. The effects of EMI are unpredictable; additional grounding and shielding might be necessary. Techniques such as using screen cages or other metal surfaces around the system, along with good grounding practices and proper storage of magnetic memory medium, are recommended. 5.3.0 Electrical Power Distribution The input line voltage to the system must be adequately rated for the loads required for the system. If possible, electrical power supplied to the system should be on an isolated circuit or on its own transformer from the main power box. Size the power system with adequate reserve for future equipment additions and installation expansion. Both the hydraulic power unit and the console controls must be considered in the electrical power distribution system, with emphasis on providing “interference free” electrical power to the controls. Control console power Control console power should be filtered from outside RF interference and line-regulated to provide 105-130 VAC or 200-240 VAC, 50-60 Hz. An isolated power source or uninterruptible power supply is recommended to reduce potential damage to components or fixturing from power loss. Make sure that the service to the system is not on a line that can be accidentally shut off. Review the individual component product manuals to ensure that the proper fuses and terminal boxes are selected for use with the equipment. Standby power The system will operate over a normal range of power frequencies and voltages. However, where facility power is excessively noisy and contains power spikes, either line regulation or the use of a uninterruptible power supply is recommended. Hydraulic power supply electrical power Electrical power is input to the HPU starter box. Ensure proper phasing when connecting electrical power to the HPU. Refer to the electrical schematic provided with the HPU product manual. Power cable access is provided into the box with the cable going from the box to the electrical service disconnect. This disconnect 38 MTS Material Test System Operation 5.0 Installation Guidelines must be provided by the customer to allow maintenance personnel to safely remove all power to the HPU. Wiring must conform to local electrical codes and regulations. 5.4.0 Grounding Requirements Each system has its own internal grounding network, which is common grounded through the green wire in the power cable and must also return to ground, through the conduit of the electrical distribution system. Note that the green wire must not be a current-carrying conductor or a neutral conductor. All equipment related to the load frame should be connected to the same electrical circuit if possible. If the computer, monitor or other peripherals are connected to a different electrical circuit (example; the load frame is connected to 208 VAC power but the computer and monitor are connected to 120 VAC power) make sure there is no voltage difference between the two different grounds. If voltage is present, damage could occur to the electronics in the machine, the computer and monitor or the peripherals being used. This must be resolved before turning on the equipment. Where electrical power is of poor quality (noise spikes, poorly regulated, and so forth) or the ground system in the facility contains electrical noise, attach a 4 AWG wire directly to the steel structure of the building, or attach a 3 m x 3 m (10 ft x 10 ft) steel plate in contact with masonry and a 4 AWG wire for the ground system. An alternate method would be to attach a 4 AWG wire directly to a good earth ground point such as a copper grounding rod driven at least 2 m (6 ft) into the ground. Grounding must conform to local electrical codes. 5.5.0 Test Controller and Console Requirements Lifting and moving Table and floor models Warning: Proper body mechanics are essential when lifting the test controller. Use of improper lifting mechanics can result in injury (musculoskeletal disorders). Keep your back straight and lift with your legs while keeping the test controller as close to your body as possible. If for any reason you can not lift the test controller by yourself, have someone assist you. The larger models are heavy and require more than one person to lift and move them. The larger units are equipped with casters that allow you to move them on a flat surface. Stand-up consoles For large stand-up consoles, lifting and moving instructions are attached to the unit. The console has casters for easy movement on smooth, level surfaces. When moving the unit using the casters, be sure that the leveling pads are screwed into the base of the cabinet. MTS Material Test System Operation 39 5.0 Installation Guidelines Due to the high center of gravity of the console, two people are required to roll the console if the floor has obstructions or bumps; use one person on each side of the console to watch for obstructions. Move the unit with the front panel controls away from the direction of travel to minimize the damage that could occur if the console tipped over. Routing cables The cable exit from the console is at the rear, through a slot below the rear door. Therefore, location of the cable trays and routing should be considered from this point. Adequate clearance must be provided for rear console access to permit cable attachment, fuse replacement and component maintenance. Cooling fans Do not block, obstruct, or in any way reduce the air flow to or from the fan. Leveling system Table and floor models Because of the relatively small footprint, there are no leveling feet on the table and floor models. These should be placed on a level surface. Stand-up consoles Because of the larger footprint, the stand-up consoles have leveling feet that allow the cabinet to be leveled as necessary. 5.6.0 Cooling Water Requirements The MTS hydraulic power unit (HPU) water connections are supplied with clamps and hose nipples for the recommended type of hoses. The common type of recommended hose is Uniroyal P-340 or an equivalent hose rated for 1.03 MPa (150 psi) operation. Shutoff valves should be included in the facility supply and drain lines to allow for unit maintenance. Note that a 0.2-0.3 MPa (30-45 psi) water pressure at a maximum of 24°C (75°F), with a flow rating corresponding to the HPU flow requirements, is necessary for proper system operation. Water flow requirements and maximum temperature are provided in the specifications table located in the HPU product manual or on the Product Information CD. 5.7.0 Connecting the System Components After electrical input power connections are made to the system console and hydraulic power unit, the hydraulic lines need to be connected. The cables between the console and various electrohydraulic components and/or transducers also need to be connected. Hydraulic Line Connections Typical system hydraulic line connections consist of hydraulic pressure, return, and drain lines from the hydraulic power unit to the hydraulic service manifold and/or actuators. Depending on the optional equipment 40 MTS Material Test System Operation 5.0 Installation Guidelines supplied with the system, some of these connections might not apply. If provided, refer to the system assembly and/or hydraulic distribution drawings (located on the system Reference Manual CD) for additional information regarding point-to-point hydraulic connections. Cable Connections MTS Systems Corporation categorizes cables as either being console cables or system cables. Console cables provide internal connections between console components and products (for example, between the 493/494 boards and a rear access panel). These cables are connected at the factory and only need to be checked for secure connection during installation of the system (that is, check that they did not come loose during shipment). For system cables, if provided, refer to the system assembly and/or console assembly drawings (located on the system Reference Manual CD) for specific information regarding connector numbers and point-to-point connections. 5.8.0 System Startup Before system startup, you should be familiar with the test fixtures, test controller or electrical console, PC workstation, hydraulic power unit, and other system components. This includes reading all of the sections in this Operation Manual and the various additional documents supplied with the system. If applicable, also read the vendor manuals supplied with the system. Observe all safety practices and operating procedures to ensure proper use of the system. Control console The console power can be turned on after verifying that the following installation procedures have been completed: • cable connections are made and secured with proper strain relief, • the power source is ready, • the components are properly grounded, and • the hydraulic power unit is shut off. PC workstation The cabling between the test controller and the computer should be checked for proper routing and secured using attachment screws where necessary. It is important that the physical integrity of these connections be maintained to ensure safe and accurate operation of the system. When turning on power to the computer, be sure that auxiliary equipment is also turned on at the appropriate time. Refer to the test controller documentation for information regarding the rear panel connectors provided for computer-controlled operation. Hydraulic power unit Ensure that electrical power is supplied to the HPU. Then turn on the HPU in low pressure and check for leakage or improper operation. The cooling water supply should also be checked for leakage or improper operation. MTS Material Test System Operation 41 5.0 Installation Guidelines Actuators After checking the electrical and hydraulic power unit connections, the actuator position control electronics (the Set Point control on the selected controller) should be checked for signal polarity and control. This is accomplished by performing the following steps: 1. Clear the area around the piston rod of obstructions. 2. Select the desired control mode (typically load). 3. Clear any active interlocks. 4. Apply hydraulic pressure by completing the following steps: a. Press the Hydraulic Pressure Low switch to start the HPU and apply low hydraulic pressure to the actuator (the Off indicator will extinguish and the Low indicator will light). b. Observe the actuator for any movement caused by hydraulic fluid pressurizing the system. Ensure that the actuator stabilizes before proceeding. c. Press the Hydraulic Pressure High switch to apply high hydraulic pressure to the actuator (the Low indicator will extinguish and the High indicator will light). 5. Slowly adjust the Set Point control on the controller and observe piston movement. The direction and response should be appropriate for the system configuration. The system phase can be determined as follows: • If the Set Point control is adjusted in a negative direction and the actuator retracts, then the system is set for a positive phase. • If the Set Point control is adjusted in a negative direction and the actuator extends, then the system is set for a negative phase. 42 MTS Material Test System Operation 6.0 Getting Started Topics: • • • • • Overview................................................................................................................................................44 Define the Test Configuration................................................................................................................44 Define the Test Parameters...................................................................................................................46 Select Test Setup Methods....................................................................................................................52 Determine the Crosshead Position........................................................................................................55 MTS Material Test System Operation 43 6.0 Getting Started 6.1.0 Overview Before setting up or operating the test system, the hardware component configuration must be defined, control settings (or test parameters) should be calculated, and test setup decisions must be made. This section describes some of the factors to consider when completing these pre-operation procedures. Define the test configuration Identifies factors to consider when selecting the hardware for a test. It also describes test controller features that can be selected for specific test applications. All of these selections must be made before power is applied to the test system. Define the test parameters The test definition contains separate definition items for a test procedure, runtime displays, report layouts, test variables, and test resources. These test parameters should be defined before beginning the operating procedure. Select test setup methods Describes the effect of the servo loop adjustments. This information should be reviewed and any necessary setup decisions should be made before beginning the operating procedure. Determine the crosshead position Describes how to determine the position of the crosshead to achieve the clearance needed for specimen installation. 6.2.0 Define the Test Configuration Test configuration definition involves determining how the mechanical components will be set up, what external equipment is necessary, and how the test controller features should be configured. The following subsections outline some of the factors to consider when defining the test configuration. 6.2.1.0 Load Unit Setup Select a load cell that is properly rated for the test. Then, ensure that the load cell is aligned with the actuator. The load cell must also be aligned whenever the actuator or crosshead is reinstalled. Determine what types of grips/fixtures will be used to secure the specimen into the load frame's force train. Consider how the load cell, specimen, and grips/fixtures are to be lifted and moved during test set up. Suitable lifting devices and supporting fixtures should be obtained and available for use. To ensure accurate test response and stability, grips/fixtures must be stiffer than the specimen. The type of grips/fixtures also affect the determination of the crosshead height. The length of the grips/fixtures must allow the actuator to be at midstroke after the specimen is installed. 44 MTS Material Test System Operation 6.0 Getting Started For balanced system operation, the load frame crosshead should be positioned so that the actuator piston rod will be at approximately midstroke when the specimen is installed into its upper and lower grips/fixtures. For detailed information on crosshead operation and specimen mounting considerations, refer to the load unit product manual. Refer to the individual grip and fixture manuals for more information on installing these components on the load frame. 6.2.2.0 Select and Set Up the Data Acquisition Equipment Most data acquisition transducers and their associated readout and acquisition devices should be set up before the system operating procedure is started. The most common data acquisition transducers that are selected for specific testing applications are strain gages. A strain gage measures the amount of specimen deformation and is typically bonded directly to specific areas on the test specimen. Refer to the appropriate product manual or vendor manual for further information on the setup of data acquisition equipment. 6.2.3.0 Set Up the Counter Select the counter end-of count function When the test controller counter is enabled and its preset count is reached during testing, it can either activate an interlock to stop the test or generate a rollover pulse to an external device (for example, an interrupt to a computer). The desired end-of-count function must be selected before hydraulic pressure is applied to the system. Select the counter interlock function The test controller counter contains an interlock that, if selected as the end-of-count function, will stop the test when an end-of-count is reached. This interlock can be configured as a program or hydraulic interlock. A program interlock stops only the program, while the hydraulic interlock stops the program and turns off the hydraulic power supply. When selecting the interlock function, consider the sensitivity of the test specimen. If, for example, an actuator is to be mounted to a fragile specimen, then a program interlock would probably be most desirable. A hydraulic interlock could cause the actuator to move when hydraulic pressure is removed and can damage the specimen or invalidate the test results. If the program interlock is selected, the counter can be used to stop the program at regular cyclic intervals during testing. When the first interval end-of-count is reached, data can be recorded, the preset count can be set to the next desired program stop count, and testing can be continued. 6.2.4.0 Set Up the Underpeak Detector The test controller underpeak detector senses when a signal fails to reach a specified level. Although any of the signals available for readout on the test controller can be selected as the underpeak detector input, the typical selection is a test controller's transducer output (feedback) signal. The signal that is input to the underpeak detector should be selected before hydraulic power is applied to the test system. When selecting or changing the underpeak detector input, ensure that only one signal is selected as the input. For example, if a displacement signal was selected for underpeak detection and load underpeak detection is now selected, ensure that the displacement signal is deselected before hydraulic power is applied. If more MTS Material Test System Operation 45 6.0 Getting Started than one signal is selected as the input, the underpeak detector will not trigger an interlock unless all of the selected signals are below the specified level. 6.3.0 Define the Test Parameters There are several test parameters that must be defined before beginning test setup and operation. These include selecting the proper calibrated range, defining the test program, calculating the Span and Setpoint control settings, and determining the levels of the various detectors: DC error, upper and lower limit, and underpeak. Before defining these test parameters, the test control mode should be known and the maximum and minimum test forces or displacements should be determined.The maximum and minimum desired forces/displacements will be used in the calculation of the detector settings and program scaling. 6.3.1.0 Select Appropriate Range To maintain accuracy over the entire testing range, the transducer feedback signal for each test controller can be scaled to take advantage of the ±10 volt signal range of the test controller. This is accomplished through the use of calibrating ranges for the various transducers. For each test conducted using the test controller, the operator must determine the range of force, acceleration, displacement, etc., that the test system will need to monitor and control. When this range represents the maximum and minimum values to be measured during the test, it is referred to as the “testing range.” Standard calibration ranges include 100% and 10% of full scale operating range. Note: It is important to understand that testing range does not reduce the static force capability of the associated actuator, but only increase the sensitivity of the electronic control and readout components. 6.3.2.0 Define Test Program To define the test program, the test control mode and the maximum and minimum test forces and/or displacements must be known. The test program commands the system to produce the calculated forces or displacements. This is accomplished by selecting an appropriate waveform (that is, a sine wave, square wave, triangle wave or ramps) and a frequency. The maximum/minimum amplitude of a waveform output by the programmer is typically ±10 volts, which represents ±100% of the selected operating range. The test controller's Span and Setpoint controls are adjusted to scale the program signal to fit the testing range. Adjusting the Span control changes the amplitude of the program command signal. Adjusting the Setpoint control changes the program command mean level offset. Adjusting the program's Span and Setpoint enables the testing system to produce the forces/displacement required for each specific test. 46 MTS Material Test System Operation 6.0 Getting Started Table 5: Effects of Span and Setpoint on Program Signal Item Description 1 Full-scale operating range 2 Testing range 3 Span affects program amplitude 4 Setpoint affects program mean level 5 Mean level offset Important: In load control, the actuator rod will move with a slight Setpoint control adjustment and will not stop until the Setpoint control is returned to 0. Until a reaction against the load cell exists, an open loop condition can cause a slight actuator rod drift (in proportion to the Setpoint offset from 0). The direction of the movement caused by the Setpoint control is determined by system phasing. Additional information can be found in the test controller’s documentation. 6.3.3.0 Calculate Error Detection Level Each controller contains an error detector that monitors the difference between the program command and the transducer feedback (DC error). When a controller is selected for active control, then the error detector will (if enabled during test setup) stop the test through the system interlock if a DC error in excess of the preset level is detected. MTS Material Test System Operation 47 6.0 Getting Started Table 6: Error detection level Item Description 1 Program command 2 Feedback 3 DC Error 4 Time lag The error detector can be preset to detect an excessive DC error. The level of acceptable DC error depends directly on the accuracy requirements of each testing situation. In static and low-frequency tests, error detectors are typically adjusted for levels that would stop the test when a specimen fractures or excessive deformation occurs. However, in higher frequency tests, the instantaneous DC error increases in proportion to command frequency and the error detectors have to be adjusted to higher levels. This is due to the time lag, or phase shift, between the program command and system response. Therefore, the error detectors are generally set to sense a loss of closed-loop control at higher command frequencies. The DC error level can also be adjusted during testing if desired. Operator experience is the best guide for adjusting the error detectors for high frequency testing. 6.3.4.0 Calculate Upper and Lower Limit Detector Levels Each controller contains upper and lower limit detectors that monitor the feedback from its associated transducer. Unlike the error detectors described in the previous subsection, the limit detectors can be enabled to shut down the test regardless of whether the controller is selected for active control. The limit detectors can be preset to detect a specific upper or lower feedback limit. When the feedback exceeds the preset upper limit detect level, the limit detector will (if enabled during test setup) stop the test 48 MTS Material Test System Operation 6.0 Getting Started through the system interlock. Likewise, if the feedback falls below the preset lower limit detect level, the limit detector will (if enabled during test setup) stop the test through the system interlock. Table 7: Upper and lower limit detector levels Item Description 1 Full-scale operating range 2 Upper limit detect level 3 Upper limit detected 4 Lower limit detect level 5 Lower limit detected The limit detectors should be set to minimize the chances of accidental damage to test specimens and test equipment. They are typically set to shut down the test system upon specimen failure in order to prevent fixturing or equipment damage. Under no circumstances should the limit detectors be relied on to protect personnel. In order to calculate the upper and lower limit detector levels, the maximum and minimum test forces or displacements must be known. However, in some cases, the upper and lower limits cannot be determined before testing. The following paragraphs describe how to determine limits in both of these situations. MTS Material Test System Operation 49 6.0 Getting Started Determining limits from known test forces or displacements If the maximum and minimum test forces or displacements are known, the limit detector levels can be determined and adjusted to the required levels before specimen installation. The test configuration, test program, and fixturing are all factors to consider when determining the limit detector levels. For example, consider the following test situation: • The test will run in displacement control • The actuator has a full-scale operating range of 6 inches (±3 inches) • The actuator is at midstroke after the specimen is installed • There is a 2-inch clearance between the fixtures and the specimen after the specimen is installed • The program is a cyclic command of ±0.5 inch With these conditions, the following displacement limit detector levels can be set: Upper Limit = +0.75 inch (+25% of full-scale operating range) Lower Limit = –0.75 inch (–25% of full-scale operating range) and the limit detector interlock can be enabled. When enabled, the limit detectors will stop actuator rod displacement when the specimen fails, shutting down the system and helping to protect the fixtures. Determining limits if test forces or displacements are not known As previously discussed, the upper and lower limits cannot always be determined before testing. For example, the load applied to a specimen from a given displacement probably cannot be determined before testing. If the maximum and minimum test force or displacement values are not known and cannot be determined before testing, the limit detectors should be adjusted to avoid unwanted system shutdown. Then, they should be properly adjusted while the test is running. Determining limits for specimen installation The upper and lower limit detector levels used for testing may prohibit specimen installation. For example, displacement limits may prevent piston rod extension or retraction when installing the specimen. Therefore, limit detector levels should also be determined for specimen installation. 6.3.5.0 Calculate Underpeak Detector Levels The test controller contains an underpeak detector that monitors a selected signal. This signal is typically a controller's transducer feedback signal. The underpeak detector can be enabled to shut down the test system when the signal fails to reach a preset minimum or maximum level. When the signal input to the underpeak detector does not reach the preset maximum detect level, the underpeak detector will (if enabled during test setup) stop the test through the system interlock. Likewise, if the signal does not reach the preset minimum detect level, the underpeak detector will (if enabled during test setup) stop the test through the system interlock. 50 MTS Material Test System Operation 6.0 Getting Started Table 8: Underpeak Detector Levels Item Description 1 Full-scale operating range 2 Maximum underpeak detect level 3 Maximum underpeak detected 4 Minimum underpeak detect level 5 Minimum underpeak detected The underpeak detector is typically set to stop a test before specimen failure. This minimizes the chance of equipment damage that may result if the specimen fractures. The following examples presume that the input to the underpeak detector is the DC controller's load transducer feedback signal. Determining underpeak levels from known test forces or displacements To calculate the underpeak detector levels, the maximum and minimum test forces or displacements must be known. If the test forces or displacements are known, the underpeak detectors should be adjusted to the required levels in the operating procedure. As with the limit detectors, the test configuration, test program, and fixturing are all factors to consider when determining the underpeak detector levels. For example, consider the following test situation: • The test will run in displacement control MTS Material Test System Operation 51 6.0 Getting Started • The input to the underpeak detector is the transducer feedback signal from a load cell with a full-scale operating range of ±25 kN • There is zero load after the specimen is installed • Specimen failure is defined as a ±20% drop in load (in respect to a +20 kN initial force at the programmed maximum and minimum displacements) With these conditions, the following underpeak detector levels can be set. Underpeak Max = +16 kN (+64% full-scale load) Underpeak Min = –16 kN (–64% full-scale load) and the underpeak detector interlock can be enabled. When enabled, the underpeak detector will stop the test when the specimen fails, shutting down the system and minimizing the chance of equipment or specimen damage. The maximum underpeak level will typically be set at a level 5% to 10% less positive (more negative) than the peak level of the selected input signal. The minimum underpeak level will typically be set at a level 5% to 10% less negative (more positive) than the valley level of the selected signal. Determining underpeak levels if test forces or displacements are not known If the desired underpeak values are not known, the underpeak detector should be adjusted to prevent damage to the test system and avoid undesired system shutdown. Then, they should be adjusted while the system is operating. 6.4.0 Select Test Setup Methods There are steps in the operating procedure that are optional or that provide optional setup/adjustment substeps. These include zeroing transducer outputs and adjusting the servo loop controls. The following subsections describe some of the factors to consider when determining how these setup adjustments should be completed. 6.4.1.0 Servo Loop Adjustments The servo loop adjustments establish the response and stability of the servo loop. Only the controllers that have been selected for active control of the test system need to be adjusted for servo loop response and stability. The required system response (DC error tolerance) and the specimen fragility should be considered when adjusting the servo loop controls. Sensitive specimens that cannot withstand potential actuator oscillation or unstable system operation, require particularly careful consideration. Optional steps are provided in the operating procedure for sensitive specimens. The following paragraphs explain how the servo loop controls affect the DC error. Gain (P) The gain adjustment determines how well the DC error will follow the program. The greater the gain, the more the servovalve opens for a given DC error. As proportional gain is increased, the DC error decreases, indicating closer tracking of the feedback to the command. The following figure shows the program and resulting transducer feedback signal with a small gain. 52 MTS Material Test System Operation 6.0 Getting Started Table 9: Gain adjustment Item Description 1 Response time 2 Program 3 Transducer feedback Increasing the gain decreases the stability margin of the system, increases the frequency of oscillation, and decreases response time. The following figure shows the effect on the transducer feedback of increasing the gain adjustment. Table 10: Gain adjustment transducer feedback Item Description 1 Response time 2 Overshoot MTS Material Test System Operation 53 6.0 Getting Started Item Description 3 Program 4 Transducer feedback If the gain is set too high, unstable system operation can result. This instability may cause specimen damage. Consequently, gain should be set as high as possible while maintaining stable system operation. Rate (D) The rate adjustment improves the servo control loop dynamic stability by reducing the overshoot at higher proportional gain settings. It reduces the system bandwidth, closing the servovalve in anticipation of achieving the commanded position through the rate of change in feedback. The following figure shows the effect of adding rate to a transducer feedback signal that has already been adjusted for gain. Table 11: Rate adjustment Item Description 1 Response time 2 Overshoot 3 Program 4 Transducer feedback Reset (I) (DC conditioners only) The reset adjustment increases system accuracy during static or low-frequency operation, when the actuator cannot keep the commanded position. It reduces the error between command and feedback by integrating out offsets in the DC portion of the feedback. 54 MTS Material Test System Operation 6.0 Getting Started Summary Servo loop adjustments are experimental and the operator should become familiar with the effects of these adjustments while using dummy specimens during both dynamic and static system operation. Because each adjustment can have some effect on the others, adjustments to the servo loop should be made using several iterations. This iteration sequence is provided in the operation section of this manual. 6.5.0 Determine the Crosshead Position For balanced system operation, the load frame crosshead must be positioned so that the based-mounted actuator piston rod will be at approximately midstroke when the specimen is installed into its upper and lower fixtures/grips. For detailed information on crosshead operation and specimen mounting considerations, refer to the load frame product manual. MTS Material Test System Operation 55 7.0 Operation Topics: • • • • • • • • Operation Overview...............................................................................................................................58 Initial Setup............................................................................................................................................58 Set Detector Levels................................................................................................................................59 Adjust Displacement Servo Loop (optional)...........................................................................................60 Install the Specimen...............................................................................................................................61 Adjust Load Servo Loop........................................................................................................................65 Set Up the Program, Detectors, Counter, and Data Acquisition............................................................67 Run the Test...........................................................................................................................................68 MTS Material Test System Operation 57 7.0 Operation 7.1.0 Operation Overview This section contains a typical operating sequence that will lead you through local test setup and operation. Detailed information can be found in the Series 793 Overview manual and various product manuals. Before starting the operating procedure The information in Getting Started, should be reviewed and fully understood before beginning the operating procedure described in this section. Getting Started contains information on the definition and calculation of test parameters that will be used during this procedure. It also contains some guidelines to consider if the operating procedure is modified. Before operating the system for the first time, make a trial run through the operating procedure by locating the controls involved without actually performing the adjustment. If any operating adjustment seems unclear, review the applicable operating and adjustment procedures described in the Series 793 Overview manual or the applicable product manual. Modifying the operating procedure This operating procedure describes the adjustments to be performed to accomplish normal operation. It does not cover all possible combinations of system set up and operation. The procedure is designed such that the system operator can gain basic system operating experience. As experience is gained with the system, the operating procedure can be modified to fit specific system configuration and testing requirements. Record any changes or modifications to the operating procedure and use the modified procedure in future testing to ensure the consistency of test results. 7.2.0 Initial Setup 1. Define the test. Calculate the test parameters and define the system configuration before proceeding with the test procedure. These calculations and configurations include the following: • Define the type of test. • Select the test control mode. • Define the test program. • Select the program source. • Calculate the forces and/or displacements to be achieved during the test. • Select the appropriate range cartridges for the control transducers. • Calculate the Span and Setpoint control settings. • Determine if transducer readouts should be zero suppressed for upper and lower limit detection settings. • Determine the DC error and (if desired) underpeak detection levels. • Determine what types of fixtures/grips will be needed to secure the specimen into the load frame. 58 MTS Material Test System Operation 7.0 Operation • Determine the position of the load frame crosshead. • Calculate the upper and lower limit detection levels to be used during specimen installation. • Calculate the upper and lower limit detection levels to be used during the test. • Determine which signals should be monitored during the test. • Select the external readout/data acquisition devices to be used during the test. • Select the appropriate data acquisition transducers for the test (typically strain gages.) 2. Set up test components. Set up the load frame, data acquisition devices, and test controller as defined in step 1. The setup tasks include the following: • Prepare the fixtures/grips, specimen, and data acquisition transducers. • Ensure that the load cell is properly rated for the test and that it is aligned with the actuator. • Ensure that the servovalve and feedback control cables are properly connected. • Verify that the test controller is correctly configured for the test and for the desired signal monitoring. • Set up the data recording/acquisition devices. 3. Turn electrical power on. Electrical power to a console-mounted controller is typically controlled by the main Power O/I switch located on the console lower front panel. Desktop of floor standing controllers typically have the Power O/I switch located on the back panel of the unit. 4. Set transducer full-scale values. The transducer full-scale values associated with the calibrated range are set up in Station Manager after Station Builder has configured the transducer (sensor). 5. Complete initial servo loop adjustments. To set the servo loop controls to levels that will ensure actuator stability, complete the following steps. To ensure actuator stability at hydraulic startup, selection of low proportional gain and stabilization settings is recommended for first-time operation or setup. When using the system for similar tests on similar specimens, this step can be eliminated after the servo loop has been properly adjusted for one test. 7.3.0 Set Detector Levels 1. If necessary, zero the force transducer readout. Zeroing the force transducer readouts compensates for any tare weights imposed on the specimen fixtures or grips. It can also provide a zero reference point for the detector level adjustments. 2. Set limit detector levels on the test controller. Limit detector adjustment procedures can be found in the Series 793 Controller Overview manual. 3. Set underpeak detector levels. Underpeak detector adjustment procedures can be found in the Series 793 Controller Overview manual. MTS Material Test System Operation 59 7.0 Operation 7.4.0 Adjust Displacement Servo Loop (optional) Note: If the test is to be run in displacement control, then displacement control loop should be tuned for optimal performance. 1. 2. 3. 4. Select displacement control. Clear active interlocks. Apply hydraulic pressure. Adjust the displacement (P) and Rate (D) controls. Note: The following steps are provided as a guide to the servo loop adjustments. Adjustment of these controls will vary depending on the test specimen and the components of the test system (for example, fixtures, type of feedback, hydraulic components, etc). As operator experience is gained, the steps can be modified to achieve the desired response. a) Set the Span control to 000. b) Set up the oscilloscope to monitor displacement feedback. Make the appropriate adjustments for amplitude and time base on the oscilloscope. c) Set up the selected programmer to output a low-frequency (1 Hz to 2 Hz) waveform. In most test situations, a square wave can be used. It will provide the most broad-band, informative response. When setting up the test system for a sensitive specimen, use a triangle or ramp waveform. A triangle or ramp waveform should contain sufficient frequency and provide sufficient response to optimize tuning without damaging the specimen. d) Start the program. e) Monitor the program command and slowly adjust the Span control for a small percentage (5% to 10%) of the maximum amplitude of the test program. f) Increase Gain (P) to get an overshoot without ringing. g) While watching the rate of decay oscillation, add Rate (D) and then readjust Gain (P) and Rate (D) iteratively. h) Verify the system response at different amplitude levels. Readjust the servo loop controls as necessary. i) Stop the program command. 60 MTS Material Test System Operation 7.0 Operation Warning: After you turn off system hydraulics, do not come near the load frame for at least 30 minutes – actuator motion is still possible. Unexpected actuator response can result in personal injury or equipment damage. Actuator motion is still possible after you turn off system hydraulics. Unexpected actuator response can result in personal injury or equipment damage. After hydraulic pressure is turned off, wait at least 30 minutes before coming near the load frame or restarting the hydraulic system. 5. Remove hydraulic pressure. Wait at least 30 minutes before coming near the load frame or proceeding with the operation procedure. 7.5.0 Install the Specimen The procedure for specimen installation depends on which load frame you have. The Model 370 Load Frame has an actuator speed switch and handset that are used for specimen installation. The other load frames (318, 331, 359) do not have these features. Once the specimen is installed, the servo loop adjustments are the same for all load frames. 7.5.1.0 Specimen Installation with Model 370 Load Frame The procedure to install a specimen varies due to the variety of test fixtures, grips, and the type of specimen being installed. This section should be considered a guideline. You need to modify this procedure to suit your equipment. Prerequisite You must have the necessary grips and/or fixturing installed. You must also have the controller set up to control the actuator movement, and you must have a test program defined. MTS Material Test System Operation 61 7.0 Operation Caution: Oil spillage can create an environmental concern and a slippery surface. Slippery surfaces can cause you to fall and incur personal injury. When changing hydraulic grips, make sure you cap or plug the hydraulic hoses when they are removed to prevent oil spillage. Promptly clean up any oil that might have spilled when hoses were removed. Warning: The crosshead is very heavy. A dropping crosshead can crush hands, damage grips, and smash specimens. Be careful when working in a crush zone. To reduce the hazards in this procedure, observe the following: Set and enable displacement interlocks to limit the actuator’s movement. Ensure that the crosshead is locked. Ensure that the columns are clean and dry. Keep your hands out of the crush zone except when performing the steps needed to complete this procedure. 1. Prepare the components for specimen installation. a. Ensure that the crosshead is locked. b. Turn on system electrical power. c. Turn on high hydraulic pressure. d. Set the actuator speed to slow. e. Enable the handset. f. Use the handset thumbwheel to move the actuator to its start position (usually mid-displacement). The starting position of the actuator depends on the type of fixtures, grips, and the test being set up. Caution: The crosshead can slowly drift down the columns if the locks are turned off and when hydraulic pressure is turned off. The crosshead can damage any test fixtures, grips, and specimen in its path. Unlock the crosshead only to reposition it. Always lock the crosshead after you have repositioned it, and never leave the crosshead unlocked. 2. Set the crosshead position. The crosshead position depends on the length of the specimen being tested, the starting position of the actuator, and the size of the fixtures or grips being used. 62 MTS Material Test System Operation 7.0 Operation Note: If possible, install a dummy specimen at this time. Use of a dummy specimen will help avoid potential damage to the test specimen when establishing the servo loop response and stability. The dummy specimen should be a representative model of the test specimen. 3. Install the specimen. Specimen installation varies according to the type of grip being used. Each type of grip requires the specimen or specimen fixture to fit properly into the grip. You should always review specimen installation procedures found in any grip product information manual. Caution: A properly gripped specimen is required for testing. An insufficiently gripped specimen can cause specimen damage, equipment damage, and the possibility of specimen fragmentation. Before testing, ensure that both grips are clamped and the specimen is secure. 4. Disable the handset and set the actuator speed control to fast. 5. If desired, zero the force transducer output . 6. If desired, zero the displacement transducer output . 7.5.2.0 Specimen Installation with 318, 331, and 359 Load Frames The procedure to install a specimen varies due to the variety of test fixtures, grips, and the type of specimen being installed. This section should be considered a guideline. You need to modify this procedure to suit your equipment. Prerequisite You must have the necessary grips or fixturing installed. You must also have the controller set up to control the actuator movement, and you must have a test program defined. MTS Material Test System Operation 63 7.0 Operation Caution: Oil spillage can create an environmental concern and slippery surface that can cause personal injury. When changing hydraulic grips, make sure you cap or plug the hydraulic hoses when removed to prevent oil spillage. Promptly clean up any oil that might have spilled when hoses were removed. Caution: The crosshead is very heavy. A dropping crosshead can crush hands, damage grips, and smash specimens. Be careful when working in a crush zone. To reduce the hazards in this procedure, observe the following: Set and enable displacement interlocks to limit the actuator’s movement. Ensure that the crosshead is locked. Ensure that the columns are clean and dry. Keep your hands out of the crush zone except when performing the steps needed to complete this procedure. 1. Select load control for specimen installation . 2. Clear active interlocks. 3. Apply hydraulic pressure . 4. Retract actuator rod . Slightly adjust the Set Point control in a direction to apply a small tensile force that will fully retract the actuator rod. (Doing this provides a known reference for measuring the crosshead position.) Warning: A reaction against the load cell can cause unexpected actuator movement. Unexpected actuator movement can cause serious injury and equipment damage. Do not touch the load cell or come in contact with the path of the actuator when measuring the crosshead height. When measuring the height of the crosshead, place the measurement away from the load frame's crosshead, load cell, and hydraulic actuator, and then sight straight across for an accurate measurement. 5. Position load frame crosshead to the desired height. 64 MTS Material Test System Operation 7.0 Operation Note: If possible, install a dummy specimen at this time. Use of a dummy specimen will help avoid potential damage to the test specimen when establishing the servo loop response and stability. The dummy specimen should be a representative model of the test specimen. Warning: Specimen installation is a hazardous procedure because of the proximity of the operator to force train components with hydraulic pressure applied. Personal injury or equipment damage can result if the operation of the analog controls and load frame are not completely understood. Use extreme caution while working near the load frame with hydraulic pressure on. Before working near the load frame, ensure that all personnel involved in the specimen installation and operation read the Safety section of this manual and the warnings and cautions in the load frame product manual. Secure specimen to upper the grip or fixture . Install the specimen into the upper fixture/grip assembly. This action differs depending on the grip or fixture. Refer to the appropriate product manual for additional information. Warning: When installing a specimen in load control, the actuator piston will continue to move until the specified load is achieved. Use of large load levels during specimen installation can result in equipment damage or personal injury. Use the smallest load level possible when installing a specimen in load control. 6. Extend actuator rod and secure specimen in the lower grip or fixture. Use the Set Point control to move the actuator rod. Install the specimen into the lower grip or fixture assembly. This action differs depending on the grip or fixture. Refer to the appropriate product manual for additional information. 7. If desired, zero the force transducer output . 8. If desired, zero the displacement transducer output . 7.6.0 Adjust Load Servo Loop If a test is to be run in load control, adjust the load control mode Gain (P), Rate (D), and Reset (I) controls. Complete the following steps to adjust the servo loop controls for the force (load) control mode. MTS Material Test System Operation 65 7.0 Operation Note: The following steps are provided as a guide to the servo loop adjustments. Adjustment of these controls will vary depending on the test specimen and the components of the test system (for example, test fixtures, type of feedback, hydraulic components, etc). As operator experience is gained, the steps can be modified to achieve the desired response. 1. Set the Span control to zero. 2. Set up the oscilloscope to monitor the program command and load signal. Make the appropriate adjustments for amplitude and time base on the oscilloscope. 3. Set up the selected programmer to output a low-frequency (1 Hz to 2 Hz) waveform. In most test situations, a square wave can be used. It will provide the most broad-band, informative response. When setting up the test system for a sensitive specimen, use a triangle or ramp waveform. A triangle or ramp waveform should contain sufficient frequency and provide sufficient response to optimize tuning without damaging the specimen. 4. Start the program. 5. Slowly adjust the Span control for a small percentage (5% to 10%) of the maximum amplitude of the actual test program. Caution: The following steps might cause actuator oscillation and unstable system operation. In some systems, actuator oscillation and unstable system operation can cause specimen or equipment damage. If sustained oscillation is not acceptable, perform the following steps instead of steps 6 to 10. 1. Increase Gain (P) to get an overshoot without ringing. 2. While watching the rate of decay oscillation, add Rate (D) and then readjust Gain (P) and Rate (D) iteratively. 3. Verify the system response at different amplitude levels. Readjust the servo loop controls as necessary. 6. Increase the Gain (P) adjustment to achieve an overshoot 7. Adjust the Rate (D) control counterclockwise to eliminate the ringing. 8. Increase the Gain (P) adjustment until ringing is observed. 9. Adjust the Rate (D) control to eliminate the ringing without excessive overshoot. 10. Adjust the Rate (D) control clockwise to eliminate any overshoot. 11. Repeat steps 6 through 10 to achieve the desired response. 12. Verify the system response at different amplitude levels by increasing the Span control setting. These amplitudes should represent at least 10% of the maximum test program amplitude. Readjust the servo loop controls as necessary (steps 6 through 10). 13. Stop the program. 14. Increase the Reset (I) control until the zero reference begins to waver. Decrease the Reset (I) control until the signal stabilizes. 15. If desired, select displacement for test control. 66 MTS Material Test System Operation 7.0 Operation 7.7.0 Set Up the Program, Detectors, Counter, and Data Acquisition Following is a brief procedure to set up the program command. Detailed information on computer-controlled set up can be found in the Series 793 Overview manual. Caution: The load and displacement signals will cut off (clip) a program signal that exceeds 100% of the full-scale operating range. Clipping a program signal could invalidate the test results. When adjusting the Span and Set Point controls, ensure that the combined span and set point percent of full-scale values do not exceed 100% of the full-scale operating range for the test. 1. Select program source. 2. Adjust program scaling. Use the Setpoint and Span controls to adjust the program scaling for the desired test results. 3. Start the program. 4. Check program scaling. To check the program scaling, select the desired signal (typically command or transducer feedback) for readout. Adjust the Span and/or Setpoint controls for the desired results. 5. Check error detectors. Once the program has started, actual error level can be monitored and the detectors set to the desired tolerance above the greatest peak DC error. When the detector is properly adjusted, the error detector interlock can be enabled. 6. Check limit detectors. Monitor the upper and lower peaks of the transducer output. If the existing upper and lower limit settings are correct for the test, enable the detector interlock. If it is necessary to change the upper or lower limit detector levels, disable the limit detector interlocks and adjust the upper and lower limit detector values to the desired levels. When adjustments are correct, enable the detector interlock. 7. If desired, check and enable the underpeak detector. Monitor the underpeak detector input signal. If the existing underpeak settings are correct for the test, enable the detector interlock. If it is necessary to change the underpeak detector levels, disable the underpeak detector interlock and adjust the underpeak detector values to the desired levels. When adjustments are correct, enable the detector interlock. 8. Stop the program. MTS Material Test System Operation 67 7.0 Operation 9. If a dummy specimen was installed (as recommended in the specimen Installation section, remove dummy specimen and install test specimen. 10. If desired, set up the Counter. MPT provides several counters. Run time counter: The Run Time counter displays the elapsed time of the current test since the last time it was reset. Channel counters: Channel Counters display a cumulative count of segments or cycles that have been applied to a specific channel since the start of the test. Sequence counters: Sequence Counters display the progress of individual processes within the test. They can be especially useful for procedures that contain nested groups, because you can configure them to show test progress within the nested structure of the procedure. Additional information on counters can be found in the Series 793 Overview manual. 11. Set up and start data acquisition devices. If necessary, set up any data acquisition or data recording devices. 7.8.0 Run the Test Once everything is set up, you are ready to run the test. 1. Start the test. a) Ensure the following are true: • Interlocks are cleared • High hydraulic pressure is applied to the station • Load tuning parameters are optimized • The test specimen is installed • Limits are set and actions are assigned • The test program is set up • The scope and meters are set up to monitor the test as desired b) On the Station Controls panel, press the Program Run button to start the test. 2. Continue the test to completion. Some tests will run to completion and stop automatically by preset interlocks (e.g., preset count, exceeded limit, specimen failure tripping the error detector) or by a computer-cycled stop function. If desired, the test can also be stopped periodically using the preset count feature of the test controller. To stop the test manually, press the Program Stop button to end the test. Record any necessary data and, if desired, resume the test by pressing the Program Run switch. When the test is complete, ensure that the test controller is in the program stop condition (press the Program Stop switch, if necessary). Remove the test specimen and record any additional data. When no additional testing is to be performed, press the Hydraulic Pressure Off switch to turn off the HPU. 68 MTS Material Test System Operation 8.0 Routine Maintenance Topics: • Maintenance Overview..........................................................................................................................70 MTS Material Test System Operation 69 8.0 Routine Maintenance 8.1.0 Maintenance Overview Caution: High pressure fluids can be present in the test system. High-pressure hydraulic fluid can cause cuts and burns. Ensure that you establish and follow standard lock out/tag out safety procedures and the test system is hydraulically isolated before you perform routine maintenance procedures on the test system. Also ensure that you allow the system to rest a minimum of 20 minutes from the time the system is hydraulically isolated before you attempt to perform maintenance on hydraulic components. Caution: Hazardous electrical current can be present in the test system. Coming in contact with high voltage electrical current can cause death or severe burns and injury. Ensure that you establish and follow standard lock out/tag out safety procedures and that the test system is electrically isolated before you perform routine maintenance procedures on the test system. Overview Routine maintenance can extend the operating life of your test system by using regular inspections and simple procedures, such as filter changes, to minimize wear and component failure. Note: You can adjust the time frame for performing these procedures based on the operating requirements of your system. This section contains a maintenance schedule table. Procedures for these maintenance requirements are found in the associated product manuals. The table includes schedules for a typically configured system. The maintenance schedule table lists the recommended routine maintenance procedures. Procedures that you can perform without special training are listed in the shaded columns of the table. Procedures that require special training are listed in the unshaded columns; you should contact MTS to perform these procedures. The following paragraphs provide additional guidelines relating to routine maintenance. How to schedule maintenance Maintenance is scheduled based on system operating time. Use machine operating time or calendar time to help you schedule maintenance procedures, as shown in the table. 70 MTS Material Test System Operation 8.0 Routine Maintenance As a guideline, for a test system that operates eight hours per day, one week will equal 40 hours, and one month will equal 160 hours. For a test system that operates up to 24 hours per day, one week will equal 160 hours and one month will equal 720 hours. When to perform visual checks Routine maintenance procedures that are scheduled on a daily or weekly basis usually involve visual checks only, and should not interfere with the operation of your test system. These checks will help you assess which procedures must be performed before running the next test. For example, the dirty filter indicator on the HPU signals that it is time to clean or change the filter. You can perform these visual checks at the start of each day and incorporate them into your preparations to run a test. Note: It is highly unlikely (unless you are running an extremely long durability type of test) that you should need to stop a test simply to perform a routine maintenance procedure. Changing the intervals You can change the time interval for performing maintenance checks, based on the operating conditions for your system. Operating conditions that affect the maintenance schedule include air quality, temperature, humidity, how often you run tests, and whether you use a pump room or a hydraulic power unit to supply hydraulic fluid to the system. Keep a log to observe trends in your system, then adjust your maintenance schedule as needed. For example, you might find that you do not have to perform daily checks of the hydraulic fluid, and decide to check it once a week instead. Additional maintenance Because of the variations in system configurations, the maintenance schedule table lists the typical procedures for the associated products. Additional maintenance procedures might be required depending on the specific product model. Refer to the product manuals for complete maintenance information. Additional maintenance procedures can be required whenever you notice decreased system performance. An example of this type of maintenance is servovalve filter replacement. Many of these procedures require additional training and should be performed by MTS service personnel. Information about analyzing hydraulic fluid is contained in the MTS Fluid Care Guide that accompanies each hydraulic power unit, and in the appendices of maintenance manuals Table 12: Routine Maintenance Calendar time Daily Running time - Hours 8 1 Week 1 Month 2 3 6 1 Year 2 Year 5 + months months months Years 40 160 320 500 1000 2,000 4,000 10,000 Hazard labels Inspect for legibility X Replace as required - Hydraulic Hoses MTS Material Test System Operation 71 8.0 Routine Maintenance Calendar time Daily Running time - Hours 8 1 Week 1 Month 2 3 6 1 Year 2 Year 5 + months months months Years 40 160 320 Inspect for leaks and wear 500 1000 2,000 4,000 10,000 X Replace MTS Hydraulic Fluid Sensory Check X Particle count MTS Analyze for contamination MTS Load Frame Set initial accumulator check interval X Check accumulator N2 precharge X Clean actuator rod and columns X Inspect actuator for leakage X Adjust Servovalve mechanical null After the valve balancing procedure (electrical compensation) has been completed and the results are judged unsatisfactory. Change servovalve filter. When servovalve performance has deteriorated. Maintain airmount pressures When the load frame sits unevenly. Check HSM filters (replace as required) X Series 505 Hydraulic Power Unit 72 MTS Material Test System Operation 8.0 Routine Maintenance Calendar time Daily 1 Week 1 Month 2 3 6 1 Year 2 Year 5 + months months months Years Running time - Hours 8 40 160 320 Check functionality of warning and interlock devices X 500 1000 2,000 4,000 10,000 MTS Conduct external inspection of the heat exchanger X Replace fluid filter X Inspect incoming power lines for loose connections or defects MTS Check auto-cooling circuit functionality X Check water hoses X Replace PLC battery MTS Controller Check cooling Perform shunt calibration X X Verify controller calibration MTS Verify Safety Circuits Check E-Stops X Check limits X Check test area guard interlocks X Check actuator speed control (370 Load Frame) X Environmental Components (optional) MTS Material Test System Operation 73 8.0 Routine Maintenance Calendar time Daily Running time - Hours 8 1 Week 1 Month 2 3 6 1 Year 2 Year 5 + months months months Years 40 160 320 Inspect furnace seals X Inspect furnace insulation X Inspect furnace heaters X Inspect furnace thermocouple X 74 MTS Material Test System Operation 500 1000 2,000 4,000 10,000 9.0 Decommission Topics: • Decommission Test System...................................................................................................................76 MTS Material Test System Operation 75 9.0 Decommission 9.1.0 Decommission Test System The decommissioning process is performed when the system is going to be moved or taken out of service. Disassembly is required when performing either of these tasks. 1. Remove specimen and fixtures. Large grips should be removed if the load frame is going to be tipped over. 2. Move the actuator piston rod down to its lowest position, fully into that cushion. 3. If the unit has hydraulic lifts move the crosshead to its lowest position and torque the manual crosshead locking bolts. However, if the unit is going to be moved, the crosshead might need to be locked at a higher position to accommodate moving the unit. If the unit has manual locks select a crosshead position that will accommodate moving the unit and torque the manual locking bolts. 4. If there are hydraulic grips on the unit, ensure that the hydraulic pressure is relieved from the grip and release ports and hoses on both grips. On large grips, position the wedge chambers to the lowest positions, similar to the unit’s piston rod as noted above. If the unit has a remote 685 grip supply, cycle the grip/release handles while reducing the pressure setting to release all pressure from the grips and hoses. Turn off the 685 grip control and disconnect electrical power. Remove the hoses. If the unit has an integrated grip control (318 and Landmark) on the frame control panel move the grip/release handle to the null position and release the pressure using the pressure release valves on the grip manifold under the control panel. 5. Turn off the HSM. 6. Turn off the HPU or shut off valves if the unit is connected to a hard line distribution system. Allow time for pressure to bleed off before closing the return shut off valve. 7. Remove the accumulator charging pressure from all accumulators. 8. Hydraulic locks can retain stored pressure. Manually bleed them if the unit is going to be stored or disassembled. 9. Isolate the system hydraulically. To isolate the system from hydraulic power requires that the hydraulic supply valve or control is closed. Depending on your system’s configuration, there is either a manual valve that must be moved to its Off position or an electronically controlled supply valve that must be turned off. Electronically controlled valves are either turned off using local controls or the system software interface controls. 10. Isolate the system from electrical power. When the system electronics, control software, and the system PC are powered down, turn off the system’s main electrical supply and disconnect all cables. 76 MTS Material Test System Operation 9.0 Decommission Warning: Warning: Residual hydraulic pressure can produce a high pressure spray. This pressurized hydraulic spray can cut you or the hydraulic fluid could be forced into your skin. Do not start this procedure unless the system has been isolated from hydraulic pressure for at least 20 minutes. Always be cautious when you loosen any hydraulic connection or remove bolts or screws from any hydraulic component. When working with hydraulic components, always loosen bolts slowly and carefully to allow any trapped fluid pressure to dissipate slowly until it is completely vented before continuing to loosen. Always wear gloves and appropriate eye protection. 11. Remove all accessible hydraulic hoses. The system does not have hydraulic reservoirs that must be drained. However, each hose and hard line will potentially have trapped oil in it. When removing the hydraulic components, ensure that you have drain pans and towels available that are sufficient to handle the drain volume of the item you are disconnecting. Use safe practices when removing hydraulic components and allow any trapped or latent pressure to dissipate safely through a loosened connection before removing the component. Cap each hose, port, and hardline component. 12. Dispose of all hydraulic fluid in accordance with all local codes regarding hazardous materials handling and disposal. 13. Disconnect all cables from the controller. 14. There are two configurations for the controller: contained in an upright console (perform step A) or floorstanding (perform step B). a) Upright consoles are lifted by an overhead lifting devise using supplied lift rings. If necessary, install lift rings in the threaded bores at the top of the control cabinet. If not already installed, the lift rings are typically stored inside the cabinet or in receptacles at the rear of the cabinet. Rig and lift the cabinet and set aside. b) Floorstanding controllers can be lifted onto a suitable cart and moved to a desired location. MTS Material Test System Operation 77 9.0 Decommission Caution: Warning: Electrical components and parts can contain hazardous chemicals and compounds. Improper disposal of hazardous chemicals and compounds can cause injury and death to people, animals, and plants. In addition, it can cause contamination of the soil, air, and water. Always refer to local codes that govern the disposal of potentially hazardous materials and follow these codes for the proper handling and disposal of these materials. 78 MTS Material Test System Operation 100-196-370 D