Strut assemblies for high frequency elastomer testing on testing machines used for damper testing

Abstract

A specimen support assembly for testing an elastomeric specimen 12 includes a first support 20 and a second specimen support 22. A force transducer and accelerometer assembly 26 is connected to a second end 20B of the first specimen support 20 opposite the elastomeric specimen 12 and includes a force transducer 28 and a first accelerometer 30 operably coupled in series with the force transducer 28, the first accelerometer 30 configured to measure the acceleration of the first end 12A of the specimen 12 when attached to the first specimen support 20 and provide a first acceleration output signal 60. An elongated strut 34 has a first end 34A connected to the force transducer and accelerometer assembly 26 opposite the first specimen support 20 and has a second end 34B opposite the first end 34A. The second accelerometer 36 is configured to measure the acceleration of the second end 12B of the test specimen 12 when attached to the second test specimen support 22 and to provide a second acceleration output signal 52.

Description

[Technical Field]

[0001] The following discussion is merely intended to provide general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.

[0002] Aspects of the present invention relate to testing machines used to test dampers, such as those used in vehicle suspensions. [Background technology]

[0003] A testing machine typically used to test dampers includes a base with a pair of vertical columns supporting a crosshead above the base. An actuator is positioned within the base, while a load cell is attached to the crosshead. The damper to be tested is secured at both ends to two specimen supports: one connected to an actuator and the other connected to a load cell. Displacement sensors, such as linear encoders, measure the specimen's displacement during testing. A typical damper test uses a vibration actuator to measure the damping constant and / or force versus velocity and / or force versus displacement of the test damper specimen. These damping characteristic excitation test frequencies are typically limited to test frequencies below 50 Hz. Dampers typically range in length from about 0.4 meters to about 1.2 meters and are typically accommodated within the testing machine by adjusting the position of the crosshead relative to the base using a lifting device that supports the crosshead above the base.

[0004] In addition to damper testing, other conventional testing machines are configured to test elastomeric specimens, such as, but not limited to, engine mounts for internal combustion engine vehicles and motor mounts for electric vehicles. Other elastomeric vehicle components that can be tested include elastomeric components within dampers. Elastomer testing is quite different from damper testing. Elastomer testing is performed at higher frequencies, e.g., greater than 400 Hz. For example, engine mounts for internal combustion engines may require vibration displacements and forces above or below 1000 Hz, while motor mounts for electric vehicles may require vibration displacements and forces above or below 3000 Hz. In the future, elastomer testing may require vibration displacements and forces above or below 5000 Hz.

[0005] The most common measurements in elastomer testing are dynamic stiffness amplitude and phase. From these two dynamic properties, other similar dynamic properties (or characteristics) can be derived. These properties are most often measured by a sine sweep or discrete stepped sine displacement input, and the measured force response as a result of this sine displacement input. From the force and displacement measurements, the dynamic stiffness amplitude (K * or K Star or K * (jw)) and phase (or phase angle or loss angle or phase(jw)) are calculated from the following equation:

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[0006] Testing machines used for elastomer testing have the same basic elements as those used for dampers: a base and a pair of vertical columns supported by the base, which in turn support a crosshead above the base. However, because elastomer test specimens are significantly smaller than dampers—e.g., about 0.1 meters to about 0.3 meters in length (or height when mounted on the elastomer testing machine)—the spacing between the crosshead and the base is significantly smaller than that of testing machines used for dampers. It should also be noted that the crosshead in a damper testing machine cannot be lowered to a position similar to that found in an elastomer testing machine due to the physical attributes of the lifting device used to move the crosshead relative to the columns and / or the overall length of the columns if the crosshead is fixedly mounted to the columns. Therefore, currently, damper testing must be performed on a testing machine specifically designed for damper testing, while elastomer testing is similarly performed on a testing machine specifically designed for elastomer testing.

[0007] This Summary and Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the shortcomings discussed in the Background. [Means for solving the problem]

[0008] Some non-limiting aspects of the present invention include a specimen support assembly for testing elastomeric specimens in a testing machine. The assembly includes a first specimen support having a first end configured to engage a first end of an elastomeric specimen and a second specimen support having a first end configured to engage a second end of the elastomeric specimen. A force transducer and accelerometer assembly is connected to the second end of the first specimen support opposite the elastomeric specimen and includes a force transducer and a first accelerometer operably coupled in series with the force transducer, the first accelerometer configured to measure acceleration of the first end of the specimen when attached to the first specimen support and provide a first acceleration output signal. An elongated strut has a first end connected to the force transducer and accelerometer assembly at the end opposite the first specimen support and has a second end opposite the first end. A second accelerometer is configured to measure the acceleration of the second end of the test specimen when attached to the second test specimen support and to provide a second acceleration output signal.

[0009] A second aspect of the present invention is a testing system for applying a load to an elastomeric test specimen. The testing system includes a base, a crosshead, and a pair of vertical columns attached to the base and the crosshead and supporting the crosshead above the base. The specimen holder assembly includes a first specimen support having a first end configured to engage a first end of the elastomeric test specimen, and a second specimen support having a first end configured to engage a second end of the elastomeric test specimen. A force transducer and accelerometer assembly is connected to the second end of the first specimen support opposite the elastomeric test specimen and includes a force transducer and a first accelerometer operably coupled in series with the force transducer, the first accelerometer configured to measure acceleration of the first end of the specimen when attached to the first specimen support and provide a first acceleration output signal. An elongated strut has a first end connected to the force transducer and accelerometer assembly opposite the first specimen support, and a second end opposite the first end. A second accelerometer is configured to measure acceleration of the second end of the specimen when attached to the second specimen support and provide a second acceleration output signal. An actuator is connected to one of the second specimen support or the second end of the elongated strut and is attached to the base. A load cell is connected to the other of the second specimen support or the second end of the elongated strut that is not connected to the actuator and is attached to the crosshead.

[0010] A third aspect is a method for testing damper and elastomer specimens using a testing machine having a base, a crosshead, a pair of vertical columns attached to the base and the crosshead that support the crosshead above the base, an actuator mounted within the base, and a load cell connected to the crosshead. The method includes mounting a damper specimen on a testing machine by forming a series connection of a first damper support coupled to an actuator, a second damper support coupled to a load cell, and a damper specimen coupled between the first damper support and the second damper support; operating the actuator to test the damper specimen; removing the damper specimen, the first damper support, and the second damper support from the testing machine; mounting an elastomeric specimen on the testing machine by forming a series connection of a force transducer and accelerometer assembly comprising an elongated strut, a force transducer and a first accelerometer, the first specimen support, the elastomeric specimen, and the second specimen support; and operating the actuator and force transducer to test the elastomeric specimen.

[0011] In some embodiments of the specimen support assembly, testing system, and testing method, the first accelerometer can be positioned between the force transducer and the elongated strut, while in other embodiments, the first accelerometer can be positioned between the force transducer and the first specimen support. The overall length of the elastomeric specimen assembly, including the specimen support, elastomeric specimen, and force and accelerometer assembly, i.e., the length from the second end of the second specimen support opposite the first end of the second specimen support to the second end of the elongated strut, is at least about 0.5 meters. In other embodiments, the overall length is at least about 0.7 meters, and in still other embodiments, the overall length is at least about 0.9 meters. Because the elongated strut is primarily responsible for providing sufficient length for the overall assembly to be used in a damper testing machine, the length of the elongated strut can be at least about 0.1 meters. In other embodiments, the elongated strut is at least about 0.25 meters, and in still other embodiments, the elongated strut is at least about 0.4 meters.

[0012] In embodiments of the testing system and method, the strut is connected to the end of the force transducer and accelerometer opposite the elastomeric specimen. Thus, the strut is of sufficient length to be operatively connected between the actuator and the load cell in combination with the force transducer accelerometer assembly, first and second specimen supports, and elastomeric specimen. Preferably, the combined length of the elongated strut, first transducer and accelerometer, first specimen support, elastomeric specimen, and second specimen support has a combined length at least equal to the length of the serially connected damper specimen support and damper specimen when all are serially connected for testing on the testing machine and a damper test is performed on the specimen. In preferred embodiments, when the vertical position of the crosshead relative to the base is adjustable and has a minimum vertical position closest to the base, this minimum distance between the end of the actuator and the load cell is longer than the length of the serially connected force transducer accelerometer assembly, first specimen support, elastomeric specimen, and second specimen support. Thus, when elastomeric testing is desired, an elongated strut can be connected in series with a force transducer accelerometer assembly having a length that, when combined with the lengths of the series-connected force transducer accelerometer assembly, first specimen support, elastomeric specimen, and second specimen support, is equal to or greater than the smallest distance between the end of the actuator and the load cell achievable by the crosshead at its lowest position.

[0013] The actuator can be connected to a second end of the second support opposite the first end of the second support, and the load cell can be connected to the second end of the elongated strut. However, in an alternative embodiment, the second end of the second support can be connected to the load cell and the second end of the elongated strut can be connected to an actuator to invert the assembly. [Brief explanation of the drawings]

[0014] [Figure 1]FIG. 1 is a schematic diagram of a damper testing system having an elastomeric specimen support assembly mounted therein and a damper support assembly adjacent to the elastomeric specimen support assembly.

[0015] [Figure 2] FIG. 1 is a cross-sectional view of an elastomeric specimen mounted in an elastomeric specimen support assembly.

[0016] [Figure 3A] FIG. 1 is a block diagram for processing signals from an accelerometer. [Figure 3B] FIG. 1 is a block diagram for processing signals from an accelerometer. DETAILED DESCRIPTION OF THE INVENTION

[0017] A testing system 10 for applying a load to an elastomeric test specimen 12 is shown in FIG. 1 and includes a base 14. A pair of vertical posts 18 are attached to the base 14 and extend vertically to support a crosshead 16 suspended above the base 14. Also referring to FIG. 2, a first test specimen support 20 has a first end 20A configured to engage the first end 12A of the elastomeric test specimen 12. A second test specimen support 22 has a first end 22A configured to engage the second end 12B of the elastomeric test specimen 12.

[0018] A force transducer and accelerometer assembly 26 is connected to the second end 20B of the first specimen support 20 opposite the elastomeric specimen 12. The force transducer and accelerometer assembly 26 includes a force transducer 28 (typically embodied as a piezoelectric force transducer) coupled to a support 29 having a first accelerometer 30. The support 29 and the force transducer 28 are coupled in series. The first accelerometer 30 is configured to measure the acceleration of the first end 12A of the specimen 12 when attached to the first specimen support 20 and provides a first acceleration output signal.

[0019] The elongated strut 34 has a first end 34A that is connected to the force transducer and accelerometer assembly 26 at the end opposite the first specimen support 20. The elongated strut 34 has a second end 34B opposite the first end 34A.

[0020] The second accelerometer 36 is configured to measure the acceleration of the second end 12B of the test specimen 12 when attached to the second test specimen support 22. The second accelerometer 36 provides a second acceleration output signal.

[0021] An actuator 40 (e.g., hydraulic or electric) is mounted to the base 14 and connected to either the specimen support 22 or the second end 30B of the elongated strut 34, depending on the overall orientation of the elastomeric specimen support assembly. A displacement sensor 39, such as, but not limited to, a linear encoder, LVDT, etc., is operatively coupled to the actuator 40 to measure and provide a displacement signal indicative of the displacement of the end of the actuator 40 and its connected specimen support. A load cell 42 is mounted to the crosshead 16 and connected to either the second specimen support 22 not connected to the actuator 40 or the remaining second end 30B of the elongated strut 34.

[0022] Although the testing system 10 is specifically designed for testing damper specimens having opposite ends connected to first and second damper supports 47 and 49, as shown generally at 13 in FIG. 1, the use of force transducers 28 and accelerometers 30 and 36 allows for the application of appropriate forces and displacements to the elastomeric specimen 12 at frequencies suitable for elastomer testing. However, as noted in the Background section, testing machines 10 designed for testing damper specimens 13 are not configured to lower the crosshead 16 close enough to the end of actuator 40 so that the elastomeric specimen 12 and the force transducers and accelerometers 26 can be directly connected in series to the end of actuator 40 and load cell 42.

[0023] One aspect of the present invention is the use of a strut 34 connected to the end of the force transducer and accelerometer 26 opposite the elastomeric test specimen. That is, the strut 34 is of sufficient length to be operatively connected between the actuator 40 and the load cell 42 in combination with the force transducer accelerometer assembly 26, the first and second specimen supports 20, 22, and the elastomeric test specimen 12. Stated another way, the combined length of the elongated strut 34, the first transducer and accelerometer 26, the first specimen support 20, the elastomeric test specimen 12, and the second specimen support 22, all connected in series for testing in the testing machine 10, has a combined length at least equal to the length of the serially connected damper specimen supports 47, 49 and damper specimen 13 when a damper test is performed on the specimen 10. Stated another way, when the vertical position of the crosshead 16 relative to the base 12 is adjustable and has a lowest vertical position closest to the base 14, this minimum distance between the end 40A of the actuator 40 and the load cell 42 is greater than the length of the series-connected force transducer accelerometer assembly 26, first specimen support 20, elastomeric specimen 12, and second specimen support 22. Thus, when elastomer testing is desired, an elongated strut 34 is connected in series with the force transducer accelerometer assembly 26. The elongated strut 34 has a length that, when combined with the lengths of the series-connected force transducer accelerometer assembly 16, first specimen support 20, elastomeric specimen 12, and second specimen support 22, is equal to or greater than the minimum distance between the end 40A of the actuator 40 and the load cell 42 achievable by the crosshead 16 at its lowest position.

[0024] The overall length of the elastomeric specimen assembly, including the specimen supports 20, 22, the elastomeric specimen 12, and the force and accelerometer assembly 26, i.e., the length from the second end 22B of the second specimen support 22 opposite the first end 22A of the second specimen support 22 to the second end 34B of the elongated strut 34, is at least about 0.5 meters long. In another embodiment, the overall length is at least about 0.7 meters long, and in yet another embodiment, the overall length is at least about 0.9 meters long. Because the elongated strut 34 is primarily responsible for providing sufficient length for the overall assembly to be used in the damper testing machine 10, the length of the elongated strut 34 can be at least about 0.1 meters long. In another embodiment, the elongated strut 34 is at least about 0.25 meters long, and in yet another embodiment, the elongated strut 34 is at least about 0.4 meters long.

[0025] 1, the actuator 40 is connected to the second end 22B of the second support 22 opposite the first end 22A of the second support 22, and the load cell 42 is connected to the second end 34 of the elongated strut 34. However, in alternative embodiments, the second end 22B of the second support 22 can be connected to the load cell and the second end 34B of the elongated strut 34 can be connected to the actuator 40, and the assembly can be reversed. Similarly, in the illustrated embodiment, the first accelerometer 30 is positioned between the force transducer 28 and the elongated strut 34; however, in alternative embodiments, the first accelerometer 30 can be positioned between the force transducer 28 and the first specimen support 20.

[0026] FIG. 2 illustrates an exemplary embodiment of an elastomeric specimen holder, including fasteners and adapters that may be advantageous for connecting various components, although these fasteners and adapters should not be considered required. Starting with end 34B of strut 34, a quick connect adapter and clamp assembly 70 with fastener 71 can be used to connect end 34B to a load cell adapter plate 72 and preload adapter 74, which are connected to load cell 42. Similarly, a quick connect clamp 76 can be used to connect end 34A to support 29, while a quick connect clamp 78 can be used to connect support 29 to force transducer 28, and a quick connector clamp and adapter assembly 80 and fastener 82 can be used to connect force transducer 28 to first specimen support 20. Studs 84 and 86 can be used with force transducer 28. Finally, a quick connector clamp and adapter assembly 88 and stud 90 are used to connect second specimen support 22 to actuator 40.

[0027] The serially connected components coupled to the elastomeric test specimens 12 allow the testing machine 10 to be selectively used to test both the damper test specimens 13 and the elastomeric test specimens 12. Generally, the method of testing the damper test specimens 13 and the elastomeric test specimens 12 using the testing machine 10 involves selectively choosing when to test the damper test specimens or alternatively when to test the elastomeric test specimens. Although these tests are performed separately and occur separated in time from one another, whether by day, month, or year, the same testing machine 10 is nevertheless used for both testing the damper test specimens and testing the elastomeric test specimens, saving both the initial outlay for just one machine with the base 14, crosshead 16, column 18, and actuator 40, as well as costs associated with maintenance, and saving laboratory space.

[0028] Beginning with testing of a damper specimen for illustrative purposes, the damper specimen 13 is attached to the testing machine 10 by forming a series connection between a first damper support 47 connected to an actuator 40 and a second damper support 49 connected to a load cell 42. The damper specimen 13 is coupled between the first damper support 47 and the second damper support 49. The actuator 40 is controlled by the system controller 41 according to the test to be performed, and appropriate and / or force signals are obtained from the load cell 42, while displacement signals are obtained from the displacement sensor 39 and correlated with the movement of the actuator 40 over time. Once testing of the damper specimen 13 is complete, the damper specimen 13, first damper support 47, and second damper support 49 are removed from the testing machine 10.

[0029] When it is desired to next perform a test on the elastomeric specimen 12, the series connection of the elongated strut 34, force transducer accelerometer assembly 26, first specimen support 20, elastomeric specimen support 12, and second specimen support 22 is constructed, in one embodiment, remotely from the testing machine 10, although the components can be sequentially attached to the testing machine 10 if desired. As noted above, the second end 34B of the strut is coupled to one of the actuator 40 or load cell 42, and the other end of the assembly, the second end of the second damper support 22, can be connected to the remaining one of the actuator 40 or load cell 42 to which the strut end 34B is not connected.

[0030] The actuators 40 and force transducers 28 are controlled by a system controller 41 to perform elastomer testing. *Force and displacement measurements for measuring dynamic elastomer properties in phase and direction can be divided into two categories: static and dynamic. Static measurements in the above configuration use linear encoder 39 and load cell 42. Dynamic measurements use piezoelectric force transducer 28 and differential acceleration between accelerometers 30 and 36. The novel configuration herein utilizes existing static measurement transducers integrated into testing machine 10, specifically load cell 42 and encoder 39. And for dynamic measurements, it utilizes transducers located closer to the specimen under test (specifically piezoelectric force transducer 28 and accelerometers 30 and 36) to reduce any dynamic error introduced in the load path of strut 34 for either force or displacement measurements that results from acceleration measurements from accelerometers 30 and 36.

[0031] A first displacement compensator or corrector 50 (FIG. 3A) described herein, which may be embodied in system controller 30, measures the vibrational displacement of the fixed side of test specimen 12 and subtracts this measured deflection from the displacement measured by the actuator rod of actuator 40, which is indicative of the displacement of the other side of test specimen 12. Referring to FIG. 3A, the resulting relative displacement output signal 51 can be determined by taking a signal 52 indicative of the displacement of that side of test specimen 12, for example, as measured via the piston actuator rod (e.g., as confirmed by double integration of accelerometer 36 to provide signal 54), and subtracting a signal 58 indicative of the displacement of the fixed side of test specimen 12 (e.g., double integration of signal 60 from accelerometer 30). The first version of the displacement compensator or corrector is shown at 50 in FIG. 3A. However, because the integration process is a linear operation, an equivalent signal can be formulated by first subtracting the signals from accelerometer 30 and accelerometer 36, and then performing a double integration on the resulting signal to derive the differential displacement, as shown in displacement compensator or corrector 50' in Figure 3B. In other words, either approach can be adopted.

[0032] It should be noted that further configurations are possible. In this further configuration, not shown, strut 34 is attached directly to actuator 40. An accelerometer support, such as support 29 for accelerometer 30, is connected to the end of strut 34 opposite actuator 40. First specimen support 20, elastomeric specimen 12, and second specimen support are connected in series to accelerometer support 29. Force transducer 28 is connected to the end of the second specimen support opposite specimen 12 and to load cell 42 at the opposite end. Force transducer 28 applies a dynamic force, while here the acceleration difference between accelerometer 30 and the acceleration compensation is permanently mounted inside load cell 42.

[0033] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. 1. A testing system for applying a load to an elastomeric test specimen, comprising: A base and The crosshead and a pair of vertical posts attached to the base and the crosshead to support the crosshead above the base; a first specimen support having a first end configured to engage a first end of the elastomeric specimen; a second specimen support having a first end configured to engage a second end of the elastomeric specimen; a force transducer and accelerometer assembly connected to a second end of the first specimen support opposite the elastomeric specimen; a force transducer; a first accelerometer operably coupled in series with the force transducer, the first accelerometer configured to measure acceleration of the first end of the elastomeric specimen when attached to the first specimen support and to provide a first acceleration output signal; a force transducer and accelerometer assembly comprising: an elongated strut having a first end connected to the force transducer and accelerometer assembly opposite the first specimen support and having a second end opposite the first end; a second accelerometer configured to measure acceleration of the second end of the elastomeric test specimen when attached to the second test specimen support and to provide a second acceleration output signal; an actuator attached to the base connected to one of the second specimen support or the second end of the elongated strut; a load cell attached to the crosshead connected to one of the second specimen support or the remainder of the second end of the elongated strut that is not connected to the actuator; A test system comprising:

2. 10. The testing machine of claim 1, wherein the combined length of the elongated strut, the force transducer and accelerometer assembly, the first specimen support, the elastomeric specimen, and the second specimen support, all connected in series for testing on the testing machine, is at least as long as the damper specimen support and damper specimen connected in series for testing on the testing machine.

3. 3. The testing machine of claim 1, wherein the actuator is connected to a second end of the second test specimen support opposite the first end of the second test specimen support, and the load cell is connected to the second end of the elongated strut.

4. The testing machine of claim 3 , wherein the first accelerometer is disposed between the force transducer and the elongated strut.

5. 4. The testing machine of claim 3, wherein the first accelerometer is disposed between the force transducer and the first specimen support.

6. 3. The testing machine of claim 1, wherein the actuator is connected to the second end of the elongated strut, and a second end of the second test specimen support opposite the first end of the second test specimen support is connected to the load cell.

7. 7. The testing machine of claim 1, wherein the vertical position of the crosshead relative to the base is adjustable with a minimum vertical position closest to the base, the minimum distance between the end of the actuator and the load cell is greater than a length of the force transducer and accelerometer assembly, the first specimen support, the elastomeric specimen, and the second specimen support connected in series, and the length of the elongated strut and the length of the force transducer and accelerometer assembly, the first specimen support, the elastomeric specimen, and the second specimen support connected in series is equal to or greater than the minimum distance between the end of the actuator and the load cell.

8. 8. The testing machine of claim 7, wherein the distance from a second end of the second specimen support opposite the first end of the second specimen support to the second end of the elongated strut is at least about 0.5 meters, including the elastomeric specimen for testing on the testing machine.

9. 8. The testing machine of claim 7, wherein the distance from a second end of the second specimen support opposite the first end of the second specimen support to the second end of the elongated strut is at least about 0.7 meters, including the elastomeric specimen for testing in the testing machine.

10. 8. The testing machine of claim 7, wherein the elongated struts have a length of at least about 0.1 meters.

11. 8. The testing machine of claim 7, wherein the elongated struts have a length of at least about 0.25 meters.

12. 1. A method for testing damper and elastomer test specimens using a testing machine having a base, a crosshead, a pair of vertical columns attached to the base and the crosshead for supporting the crosshead above the base, an actuator mounted within the base, and a load cell connected to the crosshead, comprising: mounting the damper test specimen on the testing machine by forming a series connection of a first damper support coupled to the actuator, a second damper support coupled to the load cell, and the damper test specimen coupled between the first damper support and the second damper support; operating the actuator to test the damper specimen; removing the damper test specimen, the first damper support, and the second damper support from the testing machine; mounting the elastomeric test specimen on the testing machine by forming a series connection of an elongated strut, a force transducer and accelerometer assembly comprising a force transducer and a first accelerometer, a first specimen support, the elastomeric test specimen, and a second specimen support; operating the actuator and the force transducer to test the elastomeric specimen; A method comprising:

13. 13. The method of claim 12, wherein the vertical position of the crosshead relative to the base is adjustable with a lowest vertical position closest to the base, the minimum distance between the end of the actuator and the load cell is greater than a length of the force transducer and accelerometer assembly, the first specimen support, the elastomeric specimen, and the second specimen support connected in series, and the length of the elongated strut and the length of the force transducer and accelerometer assembly, the first specimen support, the elastomeric specimen, and the second specimen support connected in series is equal to or greater than the minimum distance between the end of the actuator and the load cell.

14. 14. The method of claim 13, wherein a first end of the second specimen support is coupled to the elastomeric specimen, and a distance from a second end of the second specimen support opposite the first end of the second specimen support to the second end of the elongated strut, including the elastomeric specimen for testing on the testing machine, is at least about 0.5 meters.

15. 14. The method of claim 13, wherein a first end of the second specimen support is coupled to the elastomeric specimen, and a distance from a second end of the second specimen support opposite the first end of the second specimen support to the second end of the elongated strut, including the elastomeric specimen for testing on the testing machine, is at least about 0.7 meters.

16. The method of claim 13 , wherein the elongated struts have a length of at least about 0.1 meters.

17. The method of claim 13 , wherein the elongated struts have a length of at least about 0.25 meters.

18. 1. An assembly for testing elastomeric specimens, comprising: a first specimen support having a first end configured to engage a first end of the elastomeric specimen; a second specimen support having a first end configured to engage a second end of the elastomeric specimen; a force transducer and accelerometer assembly connected to a second end of the first specimen support opposite the elastomeric specimen; a force transducer; a first accelerometer operably coupled in series with the force transducer, the first accelerometer configured to measure acceleration of the first end of the elastomeric specimen when attached to the first specimen support and to provide a first acceleration output signal; a force transducer and accelerometer assembly comprising: an elongated strut having a first end connected to the force transducer and accelerometer assembly opposite the first specimen support and having a second end opposite the first end; a second accelerometer configured to measure acceleration of the second end of the elastomeric test specimen when attached to the second test specimen support and to provide a second acceleration output signal; An assembly comprising:

19. 20. The assembly of claim 18, wherein the first accelerometer is disposed between the force transducer and the elongated strut.

20. 20. The assembly of claim 18, wherein the first accelerometer is disposed between the force transducer and the first specimen support.

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