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Copyright information Trademark information Publication information 2 © 1993, 1999, 2001, 2008 MTS Systems Corporation. All rights reserved. MTS is a registered trademark of MTS Systems Corporation within the United States. This trademark may be protected in other countries. Manual Part Number Publication Date 150319-01 A August 1993 015-031-901 B September 1999 015-031-901 C February 2001 015-031-901 D November 2001 015-031-901 E March 2008 Manual Template 4.
Contents Technical Support 5 How to Get Technical Support Before You Contact MTS 5 5 If You Contact MTS by Phone 6 Problem Submittal Form in MTS Manuals 7 Preface 9 Before You Begin Conventions 9 10 Documentation Conventions 10 Introduction 13 Misalignment 15 About Concentric Misalignment Adjust Concentric Alignment 16 About Angular Misalignment 17 Adjust Angular Alignment 15 18 Safety Information 21 Hazard Placard Placement 21 Installation 23 Series 609 Alignment Fixture Product Inf
Specimen Preparation 29 About Gaged Specimens 29 Round Thick Diameter Specimens 31 Calculating Bending Strain—Round Thick Diameter Specimens Round Thin Diameter Specimens 34 Calculating Bending Strain—Round Thin Diameter Specimens Flat Thick Specimens 35 37 Calculating Bending Strain—Flat Thick Specimens Flat Thin Specimens 32 38 40 Calculating Bending Strain—Flat Thin Specimens Notched Round Thick Diameter Specimens 41 42 Calculating Bending Strain—Notched Round Thick Diameter Specimens Not
How to Get Technical Support Technical Support How to Get Technical Support Start with your manuals The manuals supplied by MTS provide most of the information you need to use and maintain your equipment. If your equipment includes MTS software, look for online help and README files that contain additional product information. If you cannot find answers to your technical questions from these sources, you can use the internet, e-mail, telephone, or fax to contact MTS for assistance.
If You Contact MTS by Phone Know information from prior technical assistance Identify the problem Know relevant computer information Know relevant software information If you have contacted MTS about this problem before, we can recall your file.
Problem Submittal Form in MTS Manuals If you are calling about an issue that has already been assigned a notification number, please provide that number. You will be assigned a unique notification number about any new issue.
Problem Submittal Form in MTS Manuals 8 Technical Support Series 609 Alignment Fixture Product Information
Before You Begin Preface Before You Begin Safety first! Before you attempt to use your MTS product or system, read and understand the Safety manual and any other safety information provided with your system. Improper installation, operation, or maintenance of MTS equipment in your test facility can result in hazardous conditions that can cause severe personal injury or death and damage to your equipment and specimen.
Conventions Conventions Documentation Conventions The following paragraphs describe some of the conventions that are used in your MTS manuals. Hazard conventions As necessary, hazard notices may be embedded in this manual. These notices contain safety information that is specific to the task to be performed. Hazard notices immediately precede the step or procedure that may lead to an associated hazard. Read all hazard notices carefully and follow the directions that are given.
Documentation Conventions 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.
Documentation Conventions 12 Preface Series 609 Alignment Fixture Product Information
Introduction The MTS Series 609 Alignment Fixture improves alignment between the upper and lower grips of your load unit. Improving alignment reduces bending strains in your specimen, which produces more accurate test results. This section discusses the consequences of having misaligned grips and the two types of adjustments that can compensate for misalignment problems: • One set of adjustments compensates for concentric misalignment. • One set of adjustments compensates for angular misalignment.
What you need to know Related products 14 Introduction MTS Systems Corporation assumes that you know how to use your controller. See the appropriate manual for information about performing any controllerrelated step in the procedures in this manual. You are expected to know how to do the following procedures: • Turn hydraulic pressure on and off. • Select a control mode. • Manually adjust the actuator position. • Install a specimen. • Define a simple test. • Run a test.
Misalignment Misalignment In uniaxial testing, perfectly aligned grips produce uniform axial tensile strains in a specimen. For grips to be perfectly aligned, their loading axes must be concentric. Mounting Surface Loading Axis Equal Strain Equal Strain Loading Axis Mounting Surface Perfectly Aligned Grips Produce Uniform Axial Strains Misalignment between the grips produces nonuniform axial strains in a specimen.
Adjust Concentric Alignment gage section. These higher strains are on opposite sides. It also has lower than average bending strains at the top and bottom of its gage section, opposite the higher strains. Actual strain readings vary with the amount of tensile load applied to the specimen. With zero or low tensile force applied to the specimen, tensile strain readings can be opposite compressive strain readings. Under higher tensile force, high tensile readings can be opposite lower tensile readings.
About Angular Misalignment Concentricity Collar Concentricity Adjustment Screws Misalignment Before and After Concentric Adjustment Improving Concentric Alignment About Angular Misalignment Angular misalignment angles the upper grip’s loading axis away from the lower grip’s loading axis. This misalignment puts a “C”-shaped bend in the specimen. A specimen with a “C” bend has a side with higher than average strains and a side opposite with lower than average strains.
Adjust Angular Alignment ++ ++ ++ Angular Misalignment Produces a “C” Bend Adjust Angular Alignment Turning the four upper adjustment screws against the angularity collar moves the housing. The mating surfaces of the angularity collar and housing are spherical. This tilts the housing as it moves. This tilt gets the grips’ faces parallel, improving their angular alignment. Improved angularity reduces the specimen’s “C” bend and the strains that go with this bend.
Adjust Angular Alignment Angularity Adjustment Screws Angularity Collar Housing Misalignment Equal Strain Equal Strain Before and After Angular Adjustment Improving Angular Alignment Series 609 Alignment Fixture Product Information Introduction 19
Adjust Angular Alignment 20 Introduction Series 609 Alignment Fixture Product Information
Hazard Placard Placement Safety Information 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 and the placard label indicates its severity.
Hazard Placard Placement 22 Safety Information Series 609 Alignment Fixture Product Information
Installation This section describes how to install the Series 609 Alignment Fixture. As shown in the following figure, the Series 609 Alignment Fixture is installed between the force transducer and crosshead. The mounting stud threads through the crosshead, through the 609 Alignment Fixture, and then screws into the force transducer. Stud Washer Stud Jackbolts (6) Preload Nut Adapter Bushing Washer Preload Nut Crosshead Alignment Fixture Force Transducer Upper Grip 25 kN (5.
Note The following procedure assumes the force transducer is mounted to the crosshead. If you have a crosshead mounted actuator, the force transducer is mounted to the base plate. Make the appropriate changes to the following procedure to compensate for this difference. To install the alignment fixture: 1. If installed, remove the upper grip. See your grip manual for procedures to remove the upper grip. Read through the procedure before removing the grips to ensure that you understand the process.
For the jackbolts, lightly lubricate the preload collar and its washer with Molykote G-n paste. Remove the jackbolts and lightly lubricate them. Reinstall the jackbolts so that they are flush with the bottom of the collar. For the preload nut, lubricate the washer and adapter bushing. Lubricate Lubricate OR Lubricate Lubricate B. Screw the mounting stud into the top of the force transducer. A styrofoam bead will make future stud removal easier.
A0 A0 Force Capacity C0 E. Install the force transducer and alignment fixture assembly into the crosshead. Carefully lower the crosshead so that the mounting stud goes through the crosshead. F. Screw the preload collar or nut onto the mounting stud. Tighten the preload collar or nut until the alignment fixture is snug against the crosshead. Ensure that the 0° mark remains facing to the front of the load unit. 4. Check the alignment of the force transducer and alignment fixture assembly.
To reduce the hazards in this procedure: • Ensure that you set and enable displacement interlocks to limit the actuator’s movement. • Ensure that the crosshead is locked. • Reduce the load unit’s hydraulic pressure to low. • Keep your hands out of the crush zone except when performing the steps needed to complete this procedure. Read along the edge. Zero Zero Read along the inside edge. 360° C. 360° Attach the dial indicator to the actuator.
F. If the TIR is 0.038 mm (0.0015 in) or less, the force transducer is accurately aligned with the actuator. Go to Step 6. If the TIR is greater than 0.038 mm (0.0015 in), the force transducer needs to be aligned with the actuator. Continue to Step 5. 5. Align the force transducer. To align a force transducer to the crosshead: A. Lightly tap the transducer with the rubber mallet to change its position until you get a TIR of 0.038 mm (0.0015 in) or less. B.
About Gaged Specimens Specimen Preparation This section shows you where to place strain gages to create a gaged specimen. Formulas are also provided as a reference during the alignment procedure.
About Gaged Specimens Because misalignment produces bending strain, many test procedures verify alignment by specifying the maximum bending strain allowed in a specimen at a given load. This is expressed as a percent of axial strain and is usually limited to 5–10% of axial strain. Specimens with strain gages are used to measure the maximum bending strain. A typical gaged specimen has three levels of strain gages in its gage section. The gages allow you to determine bending strains at each level.
Round Thick Diameter Specimens Round Thick Diameter Specimens A typical gaged specimen has three levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produce a profile of the grip alignment. Gage placement Use twelve gages on large diameter round specimens. Attach and number them as shown here.
Calculating Bending Strain—Round Thick Diameter Calculating Bending Strain—Round Thick Diameter Specimens This section shows how to calculate the bending strain for round specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Calculating Bending Strain—Round Thick Diameter Use this formula to find the average axial strain (A): Where: Upper Gages Middle Gages ε1 + ε2 + ε3 + ε4 Au = --------------------------------------4 ε5 + ε6 + ε7 + ε8 Am = --------------------------------------4 Lower Gages ε 9 + ε 10 + ε 11 + ε 12 Al = ---------------------------------------------4 ε1 through ε12 are the strain readings from gages 1 through 12 Au is the average strain of the upper gages Am is the average strain of the middle gages Al
Round Thin Diameter Specimens Round Thin Diameter Specimens A typical gaged specimen has three levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produce a profile of the grip alignment. Gage placement On small diameter specimens where you cannot use four gages at each level, use three gages at each level. Attach and number the nine gages as shown here.
Calculating Bending Strain—Round Thin Diameter Calculating Bending Strain—Round Thin Diameter Specimens This section shows how to calculate the bending strain for round specimens with three gages at each level. Gage Placement 1. Calculate the average axial strain for each level.
Calculating Bending Strain—Round Thin Diameter 4. Calculate the direction of the maximum strain for each level. Use this formula to find the direction (φ) of the maximum (most tensile) bending strain: Upper Gages bu --------2 + 0.5 bu 1 φ = arc tan ----------------------0.866 Where: Middle Gages Lower Gages bm 2 ---------- + 0.5 bm 1 φ = arc tan ----------------------0.866 bl 2 ------- + 0.5 bl 1 φ = arc tan -------------------0.
Flat Thick Specimens Flat Thick Specimens A typical gaged specimen has three levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produces a profile of the grip alignment. Gage placement Use twelve gages on thick flat specimens. Attach and number them as shown here.
Calculating Bending Strain—Flat Thick Specimens Calculating Bending Strain—Flat Thick Specimens This section shows how to calculate the bending strain for flat specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Calculating Bending Strain—Flat Thick Specimens 3. Calculate the percent bending strain for each level.
Flat Thin Specimens Flat Thin Specimens A typical gaged specimen has three levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produces a profile of the grip alignment. Gage placement Use twelve gages on thin flat specimens. Attach and number them as shown here.
Calculating Bending Strain—Flat Thin Specimens Calculating Bending Strain—Flat Thin Specimens This section shows how to calculate the bending strain for round specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Notched Round Thick Diameter Specimens Where: See the definitions above. Notched Round Thick Diameter Specimens A typical notched gaged specimen has two levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produces a profile of the grip alignment. Gage placement Use eight gages on large diameter round specimens. Attach and number them as shown here.
Calculating Bending Strain—Notched Round Thick Calculating Bending Strain—Notched Round Thick Diameter Specimens This section shows how to calculate the bending strain for round specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Notched Round Thin Diameter Specimens Upper Gages ε1 + ε2 + ε3 + ε4 Au = --------------------------------------4 Where: Lower Gages ε5 + ε6 + ε7 + ε8 Al = --------------------------------------4 ε1 through ε8 are the strain readings from gages 1 through 8 Au is the average strain of the upper gages Al is the average strain of the lower gages 4. Calculate the percent bending strain for each level.
Calculating Bending Strain—Notched Round Thin 1 2 3 4 5 6 0° 120° 240° Gage Placement—Notched Three Gage Round Specimens • Place the gages at the top, middle, and bottom of the gage section. Space them at 120° intervals. • Place the top set of gages so that their upper edges just touch the upper edge of the gage section. • Place the bottom set of gages so that their lower edges just touch the bottom of the gage section.
Calculating Bending Strain—Notched Round Thin 1. Calculate the average axial strain for each level. Use this formula to find the average axial strain (A): Where: Upper Gages Lower Gages ε1 + ε2 + ε3 Au = --------------------------3 ε4 + ε5 + ε6 Am = --------------------------3 ε1 through ε6 are the strain readings from gages 1 through 6 Au is the average strain of the upper gages Al is the average strain of the lower gages 2. Calculate the bending strain for each axis and each level.
Calculating Bending Strain—Notched Round Thin Where: (φ) is measured from the highest reading (most tensile) strain gage toward the second highest reading strain gage b1 is the highest strain reading of a given level b2 is the second highest reading of a given level The bending strain directions for all levels should generally agree if you have satisfactorily removed the “S” bend. 5. Calculate the maximum bending strain for each level.
Notched Flat Thick Specimens Notched Flat Thick Specimens A typical gaged specimen has two levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produces a profile of the grip alignment. Gage placement Use eight gages on thick flat specimens. Attach and number them as shown here.
Calculating Bending Strain—Notched Flat Thick Calculating Bending Strain—Notched Flat Thick Specimens This section shows how to calculate the bending strain for flat specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Calculating Bending Strain—Notched Flat Thick Where: Upper Gages Lower Gages Bu PBS = ------- × 100 Au Bl PBS = ----- × 100 Al Bu is the bending strain of the upper gages Bl is the bending strain of the lower gages Au is the average strain of the upper gages Al is the average strain of the lower gages 4. Determine which axis is bending. 50 Specimen Preparation • Bending strain along one axis (usually the y axis) can be corrected by clamping and unclamping the specimen.
Notched Thin Flat Specimens Notched Thin Flat Specimens A notched gaged specimen has two levels of strain gages. The gages allow you to determine bending strains at each level. Analysis of the strain readings produces a profile of the grip alignment. Gage placement Use eight gages on thin flat specimens. Attach and number them as shown here.
Calculating Bending Strain—Notched Thin Flat Calculating Bending Strain—Notched Thin Flat Specimens This section shows how to calculate the bending strain for round specimens with four gages at each level. Gage Placement 1. Calculate the bending strains for each level.
Calculating Bending Strain—Notched Thin Flat • Bending strain along one axis (usual the y axis) can be corrected by clamping and unclamping the specimen. • Bending strain along the other axis (usually the x axis y axis) can be corrected by using the alignment fixture.
Calculating Bending Strain—Notched Thin Flat 54 Specimen Preparation Series 609 Alignment Fixture Product Information
Alignment Procedure This section covers alignment using the two most common gaged specimens. They are the round specimen with three gage levels, four gages per level and the thin flat specimen, also with three gage levels, four gages per level. Note It is important to start with the force transducer and actuator aligned. The Series 609 Alignment Fixture is a precision instrument not intended to correct gross misalignments.
Installing a Gaged Specimen Installing a Gaged Specimen In this section, you clamp the gaged specimen and get ready to measure bending strain. WARNING You will be working in a crush zone when installing the gaged specimen. If you are not careful, you could crush anything, including your hands, between the grips. Ensure that the crosshead is locked, appropriate limit detectors are enabled, and tongs are used to handle the specimen. 1. Turn on electrical power at your test controller.
Installing a Gaged Specimen Select force control as your active control mode. Select the most sensitive operating range. Set and enable displacement interlocks to limit the actuator’s movement. Or, select a channel-limited-channel control mode that emulates the configuration described here. 3. Turn on high hydraulic power. 4. Adjust the actuator to near mid-displacement. 5. Position the crosshead so that there is room to install the specimen into the grips. Lock the crosshead.
Adjust the Concentric Alignment Adjust the Concentric Alignment In this section, you move the upper grip laterally to reduce the specimen’s “S” bend. You will probably end up with readings characteristic of a “C” bend— tensile and compressive readings on opposite sides of the specimen. 1. Refer to your ASTM Standard Test Method (or other appropriate standard) for the maximum bending strain permitted. Note Your test specification permits a maximum 10% bending strain.
Adjust the Concentric Alignment 3. Using the following figure, determine which screws to adjust. This figure shows how turning the concentricity adjustment screws affects strain gage readings. Note Tighten Loosen If the screws can not be adjusted, reduce the preload by 50% Move This reading moves positive This reading moves negative This reading moves negative This reading moves positive • If you are making minor adjustments, keep all four screws in contact with the concentricity collar.
Adjust the Concentric Alignment Adjust Strain Readings Upper Middle Lower s (typical readings before adjustment) t (typical readings after adjustment) Upper Middle Lower Round Specimens—Reduce the “S” Bend Round specimens with three gage levels, four gages per level–adjust the concentricity adjustment screws to move the upper and lower readings toward the middle gage readings.
Adjust the Concentric Alignment The following figure shows typical readings before and after an adjustment. B side A side Adjust Strain Readings A B Upper Middle Lower s (typical readings before adjustment) t (typical readings after adjustment) Upper Middle Lower Thin Flat Specimens – Reduce the “S” Bend If you are using thin flat specimens with three gage levels, four gages per level, adjust the concentricity adjustment screws to move the upper and lower readings toward the middle gage readings.
Adjust the Concentric Alignment 5. Continue to adjust concentricity screws to reduce the “S” bend as much as possible. You should end up with readings characteristic of the remaining “C” bend which has uniformly higher readings on one side of the specimen and uniformly lower readings on the specimen’s opposite side.
Adjust the Angular Alignment Adjust the Angular Alignment An angular adjustment tilts the Series 609 Alignment Fixture to reduce the angular misalignment that puts a “C” bend in the specimen. Strain Gage Find maximum bending strain and srtain direction—all Record Readings Record Readings Record Readings Top View Find Each Level’s Maximum Bending Strain and Direction 1. Record the strain gage readings at each level. Calculate each gage level’s maximum bending strain and, if necessary, its direction.
Adjust the Angular Alignment 2. Using the following figure, determine which screws to adjust. Loosen Tighten These readings move negative These readings move positive Turning the Angularity Screws • If you are making minor adjustments, keep all four screws in contact with the concentricity collar. • If you are making adjustments of 75 µS or more, loosen the opposing screws. Tighten one to get a reading slightly beyond your goal. Tighten the other to reach your goal. End with all screws tight.
Adjust the Angular Alignment Adjust Strain readings Upper Try for zero readings Middle Lower s (typical t (typical Upper Middle Close to zero Lower Round Specimens—Reduce the “C” Bend If the magnitude of the middle gages’ readings change, you are overadjusting the angularity screws. Keep adjusting the screws to bring the readings closer together. Stop when your readings start to move apart. For example, if your original middle 180° reading goes from -15 to +15, you have overadjusted.
Adjust the Angular Alignment The following figure shows typical readings before and after an adjustment. Adjust B side A side Strain readings Upper Middle Lower Try for zero readings s (typical readings before adjustment) t (typical readings after adjustment) Upper Middle Close to zero Lower Thin Flat Specimens—Reduce the “C” Bend Thin flat specimens with three gage levels, four gages per level, turn the angularity adjustment screws to try to get equal readings from all four middle level gages.
Check the Alignment Strain Gage Find maximum bending strain direction—all levels Record Settings Record Settings Record Settings Top View Find Each Level’s Maximum Bending Strain and Direction 3. Calculate each gage level’s maximum bending strain and, if necessary, its strain direction. If all strains fall within specifications, go to Step 1 of the next section. If not, go to Step 4. 4. Clamp and unclamp both ends of the specimen, one end at a time.
Check the Alignment CAUTION Your gaged specimen may not be strong enough to handle the full test force without being damaged. You may have to use lower clamping and tensile forces than you will use on actual specimens. 2. Adjust your grip supply to apply a clamping force sufficient to hold the gaged specimen under the tensile force you will apply. 3. Apply a force that is as close as possible to the test force you will use on your actual test specimens. 4. Record the strain readings at each gage level.
m MTS Systems Corporation 14000 Technology Drive Eden Prairie, Minnesota 55344-2290 USA Toll Free Phone: 800-328-2255 (within the U.S. or Canada) Phone: 952-937-4000 (outside the U.S. or Canada) Fax: 952-937-4515 E-mail: info@mts.com Internet: www.mts.
