Test fixture and test method

Abstract

A test jig of the present invention uses a vibration generating device that can excite vibration in only one axis, and simultaneously applies excitation forces in multiple axes to a test piece, and can easily change the ratio of the excitation forces in each axis. It includes a vibration generating device connection portion (1) connected to a vibration generating device and which excites vibration in the z-axis direction; a first vibration plate (2) connected to the vibration generating device connection portion (1) and which extends in a cantilevered manner in the x-axis direction intersecting the z-axis direction; a second vibration plate (3) connected to the vicinity of the x-axis direction end portion of the first vibration plate (2) and which extends in a cantilevered manner in the y-axis direction intersecting the z-axis direction and the x-axis direction; and a test piece setting portion (5) provided with a test piece and which receives vibration from the vibration generating device connection portion (1) via the first vibration plate (2) and the second vibration plate (3), at least one of the first vibration plate (2) and the second vibration plate (3) having a length adjustment mechanism (6).

Description

Technical Field

[0001] This invention relates to test fixtures and test methods. Background Technology

[0002] A testing technique called HALT (Highly Accelerated Limit Test) applies excessive loads such as temperature and vibration to prototypes during the product design phase, allowing for early identification of vulnerable areas when the prototype is commercialized. As a testing device suitable for this technique, for example, a HALT device capable of simultaneously withstanding random vibrations and sudden temperature changes in multiple axes has been commercialized.

[0003] On the other hand, vibration generating devices that can vibrate in only one axial direction are also widely used, mainly for verifying the reliability of products to vibration. As for the technology related to vibration generating devices and their test fixtures that can vibrate in one axial direction, the technology described in Patent Documents 1 and 2 is known, for example.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-055777

[0007] Patent Document 2: Japanese Patent Application Publication No. 2000-258290

[0008] Patent Document 3: Japanese Patent Application Publication No. 10-073512 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] Typically, HALT-specific equipment is used during HALT testing. HALT-specific equipment is not only expensive in itself, but also consumes significant amounts of liquid nitrogen and electricity when cooling the equipment or drastically changing the test environment temperature. Therefore, the cost of evaluation is higher compared to using a single-axis testing setup. Consequently, there is a need for evaluation at a lower cost.

[0011] In contrast, it is known that, depending on the product's failure mode, simultaneous vibration in multiple axial directions results in a shorter lifespan compared to vibration in only one axial direction. Furthermore, depending on the product, sample evaluation can be performed using, for example, the testing apparatus described in Patent Document 3, even without using a dedicated HALT apparatus.

[0012] Patent document 3 discloses a testing apparatus that uses a vibration tester to excite a sample in one direction and measure the excitation intensity. The sample is mounted on an inclined clamp, and by exciting it in one direction, both vertical and horizontal excitation forces are applied to the sample, thereby extracting vulnerable areas. This testing apparatus can reduce the cost of evaluation.

[0013] However, in the test apparatus of Patent Document 3, there is a problem that it is difficult to independently adjust the excitation force applied to the sample in the vertical and horizontal directions. Therefore, there is a need for a test fixture that, in order to extract vulnerable parts, can simultaneously excite the sample in multiple axial directions by mounting it on a vibration generator that can only excite in one axial direction, and can easily change the excitation force in each axial direction at various ratios.

[0014] The present invention was made in view of the above-mentioned problems, and its object is to provide a test fixture and test method, which uses a vibration generating device that can only excite in one axial direction to simultaneously apply excitation forces in multiple axial directions to the test specimen, and can easily change the ratio of excitation forces in each axial direction.

[0015] Technical means for solving technical problems

[0016] To address the above problems, one representative test fixture of the present invention includes:

[0017] A vibration generator connection part, which can be connected to the vibration generator and excite vibration in the z-axis direction;

[0018] A first vibrating plate is connected to the vibration generating device connection part and extends in a cantilever shape in the x-axis direction intersecting the z-axis direction;

[0019] A second vibrating plate is connected near the x-axis end of the first vibrating plate and extends cantileveredly in the y-axis direction, which intersects the z-axis and the x-axis directions; and

[0020] The specimen setting section is used to set the specimen and receive vibration from the vibration generating device connection section via the first and second vibrating plates.

[0021] At least one of the first vibrating plate and the second vibrating plate has a length adjustment mechanism.

[0022] Invention Effects

[0023] According to the present invention, a test fixture and test method are provided, which uses a vibration generating device that can only excite in one axial direction to simultaneously apply excitation forces in multiple axial directions to the test specimen, and can easily change the ratio of excitation forces in each axial direction.

[0024] Other technical issues, structures, and effects not mentioned above will be further clarified through the following description of the implementation methods. Attached Figure Description

[0025] Figure 1 This is a schematic perspective view showing the structure of the test fixture according to Embodiment 1.

[0026] Figure 2 This is a diagram showing an example of a length adjustment mechanism.

[0027] Figure 3 This is a diagram showing an example of a length adjustment mechanism.

[0028] Figure 4 This is a side view diagram before the vibration test begins.

[0029] Figure 5 It is a deformation diagram during the vibration test.

[0030] Figure 6 This is a diagram showing a two-dimensional material mechanics model.

[0031] Figure 7 It is a deformed diagram of a two-dimensional material mechanics model.

[0032] Figure 8 This is a deformation diagram of the first vibrating plate in a two-dimensional material mechanics model.

[0033] Figure 9 This is a diagram showing a two-dimensional material mechanics model.

[0034] Figure 10 This is a diagram showing the finite element analysis model.

[0035] Figure 11 This is a graph showing the results of the finite element analysis.

[0036] Figure 12 This is a graph showing the results of the finite element analysis.

[0037] Figure 13 This is a graph showing the results of the finite element analysis.

[0038] Figure 14 This is a graph showing the results of the finite element analysis.

[0039] Figure 15 This is a diagram showing the finite element analysis model.

[0040] Figure 16 This is a graph showing the results of the finite element analysis.

[0041] Figure 17 This is a graph showing the results of the finite element analysis.

[0042] Figure 18 This is a graph showing the results of the finite element analysis.

[0043] Figure 19 This is a schematic perspective view showing the structure of the test fixture according to Embodiment 2. Detailed Implementation

[0044] Hereinafter, preferred embodiments for carrying out the present invention will be described with appropriate reference to the accompanying drawings. However, the present invention is not limited to the embodiments listed herein, and appropriate combinations or modifications can be made without changing the essence.

[0045] In this specification, "effective length of the vibrating plate" refers to the distance between the points where the axes of the vibrating plates intersect when one end of the vibrating plate is joined to another vibrating plate. When one end of the vibrating plate is joined to the connection part of the vibration generating device or the specimen placement part, and the other end of the vibrating plate is joined to another vibrating plate, it refers to the distance between the point where the axis of the vibrating plate intersects the connection part at one end and the point where it intersects the axis of the other vibrating plate at the other end. Furthermore, "length adjustment device" refers to a device used to adjust the effective length of the vibrating plate.

[0046] Furthermore, in the following implementation, the case where the x-axis, y-axis, and z-axis are orthogonal (Cartesian coordinate system) is used as an example. However, it is equally applicable even when the x-axis, y-axis, and z-axis are obliquely intersecting (oblique coordinate system).

[0047] Implementation Method 1

[0048] Figure 1 This is a schematic perspective view showing the structure of the test fixture. The test fixture 100 consists of a vibration generating device connection part 1, a first vibration plate 2, a second vibration plate 3, a third vibration plate 4, and a test specimen mounting part 5. The vibration generating device connection part 1 is connected by bolts or the like to a vibration generating device 9 (see reference 1) capable of excitation in one axial direction. Figure 4 , Figure 5 ).

[0049] Here, the vertical direction is defined as the z-axis, and the directions orthogonal to the z-axis are defined as the x-axis and y-axis. The x-axis and y-axis are orthogonal to each other.

[0050] The first vibrating plate 2 is connected adjacent to the vibration generating device connection part 1, orthogonal to the vibration direction (z-axis direction) of the vibration generating device, and extends in a cantilever shape in the x-axis direction. The second vibrating plate 3 is connected to the vicinity of the end of the first vibrating plate 2 and extends in a cantilever shape in the y-axis direction. The third vibrating plate 4 is connected to the vicinity of the end of the second vibrating plate 3 and extends along the z-axis direction. That is, the first vibrating plate 2, the second vibrating plate 3, and the third vibrating plate 4 are orthogonal to each other. The specimen placement part 5 is located near the end of the third vibrating plate 4, and the specimen used as the test object can be fixed using bolts or the like.

[0051] Since a smaller mass and higher stiffness of the test fixture 100 result in a higher resonant frequency, it is easier to avoid resonance of the test fixture in the test frequency band. Therefore, it is preferable to use a material with a lower specific gravity and higher stiffness. In addition, it is preferable to use a material with sufficient strength and fatigue strength that can suppress deformation, breakage and fatigue failure caused by the load during vibration testing.

[0052] The material used for the test fixture 100 can be, for example, metals such as iron, aluminum, or alloys with these as the main components, or composite materials such as FRP (Fiber Reinforced Plastics). Metals generally have the advantage of good processability. On the other hand, composite materials, although generally having a lower specific gravity, have the advantages of higher stiffness and strength.

[0053] The cross-sectional shapes of the first vibrating plate 2, the second vibrating plate 3, and the third vibrating plate 4, in addition to the following... Figure 1 Besides the solid rectangle shown, it can also be a square or H-shaped cross-section with an internal cavity. When the cross-section is a solid rectangle, it has advantages such as easy installation and ease of machining and installation, for example, ensuring threaded holes for fastening. On the other hand, when the cross-section is square or H-shaped, compared to the solid rectangle, it has the advantage of not significantly reducing stiffness while reducing mass.

[0054] At least one of the first vibrating plate 2, the second vibrating plate 3, and the third vibrating plate 4 has a length adjustment mechanism 6. The length adjustment mechanism 6 is a mechanism for relatively changing the effective length of the first vibrating plate 2, the second vibrating plate 3, and the third vibrating plate 4 in the path connecting the vibration generating device connection part 1 to the test specimen setting part 5.

[0055] Figure 2 , Figure 3 An example of the length adjustment mechanism 6 is shown. For example, as... Figure 2As shown, a long, narrow hole (also called an elongated hole, hereinafter the same) 12 is provided in the first vibrating plate 2 opposite to the second vibrating plate 3, allowing a pin (also called a fastener) 14 with external threads at its front end to be screwed into the internally threaded hole of the second vibrating plate 3 through the hole 12. The position relative to the first vibrating plate 2 is fixed by firmly tightening the pin 14. By loosening the pin 14 and allowing relative movement along the elongated hole 12, the second vibrating plate 3 can be moved relative to the long side of the first vibrating plate 2. This mechanism allows the effective length of the first vibrating plate 2 in the path connecting the vibration generating device connection part 1 to the test specimen setting part 5 to be changed. The length adjustment mechanism 6 is constituted by the pin 14 and the hole 12. A general-purpose bolt can also be used instead of the pin as a fastener.

[0056] Similarly, an elongated hole 13 is provided on the second vibrating plate 3, opposite to the second vibrating plate 3, so that a pin 15 with an external thread at its front end is screwed into the internal threaded hole of the third vibrating plate 4 through the hole 13, and its position relative to the second vibrating plate 3 is fixed by firmly tightening the pin 15. By loosening the pin 15 and allowing relative movement along the elongated hole 13, the third vibrating plate 4 can be moved relative to the long side of the second vibrating plate 3. With this mechanism, the effective length of the second vibrating plate 3 in the path connecting the vibration generating device connection part 1 to the test specimen setting part 5 can be changed. The pin 15 and the hole 13 constitute the length adjustment mechanism 6.

[0057] Figure 3 This is a side view showing only the vibrating plate 4 near the third vibrating plate. For example, as... Figure 3 As shown, a third vibrating plate 4 is formed by combining two components 4a and 4b. The upper component 4a has a continuously arranged thick plate portion 4c and a thin plate portion 4d protruding downwards from the thick plate portion 4c. The lower component 4b has a continuously arranged thick plate portion 4e and a thin plate portion 4f, the thin plate portion 4f protruding upwards from the thick plate portion 4e and slidably contacting the thin plate portion 4d. The thicknesses of the thick plate portions 4c and 4e are equal, and the thicknesses of the thin plate portions 4d and 4f are equal and half the thickness of the thick plate portions 4c and 4e.

[0058] An elongated hole 16, opposite to and extending vertically from the thin plate portion 4f, is provided in the thin plate portion 4d. A pin 17 with an external thread at its front end is screwed into the internally threaded hole of the thin plate portion 4f through the hole 16, and its position is fixed by securely tightening the pin 17. By loosening the pin 17, relative movement along the elongated hole 16 is allowed, thereby changing the distance between the thick plate portions 4c and 4e of the third vibrating plate 4, and thus changing the total length of the third vibrating plate 4, i.e., the effective length. The pin 17 and the hole 16 constitute the length adjustment mechanism 6.

[0059] Here, an example of the length adjustment mechanism 6 is shown, however, Figure 3The mechanism shown can be applied to either the first vibrating plate 2 or the second vibrating plate 3. Additionally, although in Figure 2 and Figure 3 The diagram illustrates an example of changing the position of each component by loosening pins 14, 15, and 17. However, actuators can also be installed at locations corresponding to pins 14, 15, and 17, thereby enabling adjustment of the relative positions of the components. In this case, ensuring reliability under vibration load during vibration testing to prevent actuator damage becomes a concern, but it offers the advantage of being able to activate the actuator even during vibration testing, allowing for effective length adjustment.

[0060] use Figure 4 , Figure 5 Explain the operation of test fixture 100. Figure 4 This is a side view diagram before the vibration test begins. Figure 5 From Figure 4 This is a schematic diagram of the deformation shape at a certain instant during a vibration test. The deformation is magnified for easier understanding.

[0061] like Figure 4 As shown, in the test fixture 100, the vibration generating device connection part on one end side ( Figure 4 (Not shown in the diagram) is connected to the vibration generating device 9 and extends in an L-shape, with the test specimen placement section on the other end ( Figure 4 The test specimen 7 is mounted on the device (not shown in the diagram). The vibration generating device 9 consists of a vibrating part 9a and a main body 9b. During the vibration test, if... Figure 5 As shown, the vibrating part 9a vibrates only along the z-axis. However, as Figure 5 As shown, due to the bending deformation generated in the test fixture 100, not only the acceleration component in the z-axis direction is generated in the test specimen 7, but also the acceleration component in the x-axis direction.

[0062] Similarly, the test fixture 100 also bends and deforms in the y-axis direction perpendicular to the paper surface, and generates an acceleration in the y-axis direction on the test specimen 7. As described above, by using the test fixture 100 and the vibration generating device 9 which can only excite in one axial direction, multiple axial excitation forces can be applied to the test specimen 7 simultaneously.

[0063] To generate accelerations of the same magnitude in the x, y, and z axes, the appropriate fixture size needs to be determined based on the mass of the specimen 7 and the material of the test fixture 100. Furthermore, if resonance occurs within the test frequency band, excessive acceleration will only be generated at that specific frequency, making the intended test impossible; therefore, the resonant frequency of the fixture also needs to be appropriately determined.

[0064] The following explains how to determine the appropriate fixture dimensions. First, for ease of understanding, consider the two-dimensional case of the xz coordinate system, and explain the method of generating accelerations of the same magnitude in the x-axis and z-axis directions while avoiding resonance within the test frequency.

[0065] Figure 6 This is a simplified schematic diagram of the test fixture 100 in the xz coordinate system, using a mechanics of materials model. Since only the deformation of the xz coordinate system is considered, the second vibrating plate 3, which exists perpendicular to the plane of the paper, is omitted here. The specimen 7 is assumed to be a point mass. The third vibrating plate 4, represented by a beam, and the first vibrating plate 2 are connected to the specimen 7. The end of the first vibrating plate 2 is constrained by the fixed end 11, and the state of being bolted to the vibration generating device is modeled.

[0066] Figure 7 This shows that at a certain instant during the vibration test, the phenomenon produced is similar to... Figure 5 The same model shape during deformation. ze The displacement in the z-axis direction of the fixed end 11 is generated by the excitation of the vibration generator. The first vibrating plate 2 has a deflection angle θ and a deflection amount u. z The bending deformation occurred, and subsequently, an x-axis displacement u also occurred in specimen 7. x .

[0067] Figure 8 Only displayed Figure 7 The model shown includes a first vibrating plate 2. If the load acting on the front end of the first vibrating plate 2 is pre-set as P1, then according to the fundamental equation for beam deformation in mechanics of materials, it can be expressed as u z =P1L1 3 / (3EI1), θ=P1L1 2 / (2EI1). Where L1 is the effective length of the first vibrating plate 2, E is the Young's modulus of the first vibrating plate 2 and the third vibrating plate 4, and I1 is the second moment of the cross section of the first vibrating plate 2.

[0068] Furthermore, if the effective length of the third vibrating plate 4 is set to L3 beforehand, then when θ is sufficiently small, u x =L3θ holds true for u. x u z In terms of u ze Small enough, u x =u z At the time of its establishment, according to L3P1L1 2 / (2EI1)=P1L1 3 / (3EI1), L3=2L1 / 3. That is to say, by setting L1 and L3 so that the relationship L3=2L1 / 3 holds, accelerations of the same magnitude can be generated in both the x-axis and z-axis directions.

[0069] Figure 9 This involves adding the masses of the test specimen 7 and the third vibrating plate 4 to form a model representing the combined mass 10 using point masses. If... Figure 7 The deformation pattern of the first vibrating plate 2 shown is understood as follows: Figure 9 If the needle's vibration follows a first-order mode, then its natural vibration frequency f n Represented as f n =1 / (2π)√(3EI1 / (M+m1 / 4) / L1 3 Where M is the mass of the composite mass 10, and m1 is the mass of the first vibrating plate 2. Therefore, as long as f n It can be excluded from the test frequency.

[0070] For example, consider setting the mass of the test specimen 7 as m0 = 0.5 kg, and setting the material of the first vibrating plate 2 and the third vibrating plate 4 as having a density of 7.85 g / cm³. 3 For iron with a Young's modulus of 200 GPa, the test frequency is below 1000 Hz. In this case, if the cross-sectional shape of the first vibrating plate 2 and the third vibrating plate 4 is set to a solid rectangle, for example, L1 = 90 mm and L3 = 60 mm, and the plate thicknesses t1 and t3 of the first vibrating plate 2 and the third vibrating plate 4 are set to t1 = t3 = 30 mm and the plate width b = 100 mm, the resonant frequency becomes 1390 Hz, which is not within the test frequency range, thus satisfying the above conditions.

[0071] Figure 10 The analytical model used in the finite element analysis for verification is shown. Deformation is constrained by the fixed end 11, and the mass m0 = 0.5 kg is evenly distributed on the specimen setting part 5. An acceleration in the z-axis direction is applied to the entire model.

[0072] Figure 11 The figure shows the acceleration response ratios in the x-axis, y-axis, and z-axis directions. Almost no acceleration is produced in the y-axis direction, while equal acceleration is produced in the x-axis and z-axis directions. Furthermore, the resonant frequency, as presumed, exceeds 1000 Hz.

[0073] Figure 12 It shows Figure 11 The ratio of the response ratios in the z-axis and x-axis directions is shown. In the calculation of the material mechanics model, since the influence of the actual structural thickness on deformation is not considered, the response ratio is exactly different from 1.0. However, it is about 0.8 in the experimental frequency range below 1000Hz. As planned, it can be verified that the x-axis and z-axis directions produce accelerations of the same order of magnitude.

[0074] By changing L1 and L3, acceleration can be generated at arbitrary ratios in both the x-axis and z-axis directions. This ratio is called the response ratio. Figure 13 , Figure 14 An example of the response ratio is shown in the figure.

[0075] Figure 13 These are the finite element analysis results when L1 = 100 mm and L3 = 75 mm. The response ratios in the z-axis and x-axis directions can be set to 1.0. Figure 14 These are the finite element analysis results when L1 = 100 mm and L3 = 75 mm. According to... Figure 14 The response ratio between the z-axis and x-axis can be set to approximately 0.5.

[0076] The two-dimensional case of the xz coordinate system has been explained here. The three-dimensional case of the xyz coordinate system can also be determined using the same method to determine the appropriate size of the experimental fixture. The deformation of the second vibrating plate 3, which is neglected in the two-dimensional study, is understood as... Figure 8 For the same beam bending, the load generated at the front end of the beam will be P2, and similarly, the deflection u z2 =P2L2 3 / (3EI2), deflection angle θ2=P2L22 / (2EI2), displacement u in the y-axis direction of specimen 7 y For u y =L3θ2. Where L2 is the effective length of the second vibrating plate 3, E is the Young's modulus of the second vibrating plate 3, and I2 is the second moment of the cross section of the second vibrating plate 3.

[0077] Under the same assumptions as in the two-dimensional study, if we consider the case where the displacements in the x-axis, y-axis, and z-axis directions are equal, then u x =u y =u z +u z2 Established. Therefore, L3P1L1 2 / (2EI1)=L3P2L22 / (2EI2)=P1L1 3 / (3EI1)+P2L2 3 / (3EI2).

[0078] Here, if we eliminate P1 and P2 and rearrange, then L3 = 2(L1 + L2) / 3. That is to say, by setting L1 and L3 so that the relationship L3 = 2(L1 + L2) / 3 holds, accelerations of the same magnitude can be generated in the x, y, and z axes respectively.

[0079] Regarding the resonant frequency, considering the deformation mode of the first vibrating plate 2, in Figure 9In this context, the total mass 10 can be understood as the sum of the masses of the specimen 7, the second vibrating plate 3, and the third vibrating plate 4, and the same formula as in the two-dimensional case can be used.

[0080] Figure 15 The diagram illustrates a fixture shape selected under the same conditions as in the two-dimensional study, where dimensions are chosen to produce accelerations of the same magnitude in the x, y, and z axes. All plates are 30 mm thick, with L1 = 90 mm, L2 = 60 mm, and L3 = 100 mm.

[0081] For this model, finite element analysis was performed, similar to the two-dimensional study. Deformation was constrained by the fixed end 11, and the mass m0 = 0.5 kg was evenly distributed on the specimen setting part 5. An acceleration in the z-axis direction was applied to the entire model.

[0082] Figure 16 The diagram shows the response magnifications along the x, y, and z axes obtained from the analysis. The resonant frequency, as predicted, exceeds 1000 Hz. Figure 17 The figure shows the ratio of the response magnification in the z-axis direction to that in the x-axis direction. Figure 18 The ratio of response magnitudes in the z-axis and y-axis directions is shown. The three-dimensional case is the same as the two-dimensional case, verifying that accelerations of the same order of magnitude are produced in the x-axis, y-axis, and z-axis directions.

[0083] Implementation Method 2

[0084] Figure 19 This is a schematic perspective view showing Embodiment 2. Compared to Embodiment 1, Embodiment 2, in addition to the first vibrating plate 2, the second vibrating plate 3, and the third vibrating plate 4, also includes a fourth vibrating plate 18 connected to the third vibrating plate 4 via a length adjustment mechanism 6. Since the structure other than this is the same as that of the above-described embodiment, repeated descriptions are omitted.

[0085] The fourth vibrating plate 18 does not need to be orthogonal to any of the first vibrating plate 2, the second vibrating plate 3, or the third vibrating plate 4. Therefore, the same effect can be achieved even when using a structure consisting of more than four vibrating plates 4. Although the structure becomes more complex, finer adjustments can be made.

[0086] Label Explanation

[0087] 1. Vibration Generator Connection Part

[0088] 2 First Vibrating Plate

[0089] 3. Second Vibration Plate

[0090] 4. Third Vibration Plate

[0091] 5. Specimen Setting Section

[0092] 6. Length adjustment mechanism

[0093] 7 test specimens

[0094] 8 Vibration direction

[0095] 9. Vibration Generator

[0096] 9a Vibration section

[0097] 9b Vibration Generator Main Body

[0098] 10 Synthesis Quality

[0099] 11 Fixed end

[0100] 12, 13, 16 holes

[0101] Pins 14, 15, and 17 (fasteners)

[0102] 18 Fourth Vibration Plate

[0103] 100 test fixtures.

Claims

1. A test fixture, characterized in that, include: A vibration generator connection part, which can be connected to the vibration generator and excites vibration in the z-axis direction; A first vibrating plate is connected to the vibration generating device connection part and extends in a cantilever shape in the x-axis direction intersecting the z-axis direction; The second vibrating plate is connected to the first vibrating plate near its x-axis end and extends in a cantilever shape in the y-axis direction, which intersects the z-axis direction and the x-axis direction. as well as The specimen setting section is used to set the specimen and receive vibration from the vibration generating device connection section via the first and second vibrating plates. At least one of the first and second vibrating plates has a length adjustment mechanism for changing the effective length of the vibrating plate in the path from the vibration generating device connection to the specimen setting part.

2. The test fixture as described in claim 1, characterized in that, The length adjustment mechanism includes: an elongated hole formed on one of the first and second vibrating plates, an internally threaded hole formed on the other of the first and second vibrating plates, and a fastener having an external thread capable of being screwed into the internally threaded hole and inserted into the elongated hole. The first and second vibrating plates are secured by screwing the external thread of the fastener into the internal threaded hole and tightening it. By loosening the external thread of the fastener from the internal threaded hole, the first and second vibrating plates can move relative to each other along the elongated hole.

3. The test fixture as described in claim 1, characterized in that, It has a third vibrating plate, which is connected to the second vibrating plate near its y-axis end and extends along the z-axis. The specimen setting section receives vibration from the vibration generating device connection section via the first vibration plate, the second vibration plate, and the third vibration plate.

4. The test fixture as described in claim 2, characterized in that, It has a third vibrating plate, which is connected to the second vibrating plate near its y-axis end and extends along the z-axis. The specimen setting section receives vibration from the vibration generating device connection section via the first vibration plate, the second vibration plate, and the third vibration plate.

5. The test fixture as described in claim 4, characterized in that, The length adjustment mechanism includes: an elongated hole formed on one of the second and third vibrating plates, an internally threaded hole formed on the other of the second and third vibrating plates, and a fastener having an external thread capable of being screwed into the internally threaded hole and inserted into the elongated hole. The second and third vibrating plates are secured by screwing the external thread of the fastener into the internal threaded hole and tightening it. By loosening the external thread of the fastener from the internal threaded hole, the second and third vibrating plates can move relative to each other along the elongated hole.

6. The test fixture as described in claim 3, characterized in that, At least one of the first vibrating plate, the second vibrating plate, and the third vibrating plate is formed by combining two components, which are formed by continuously providing a thick plate portion and a thin plate portion, respectively, and the thin plate portions are connected to each other by the length adjustment mechanism.

7. The test fixture as described in claim 4, characterized in that, At least one of the first vibrating plate, the second vibrating plate, and the third vibrating plate is formed by combining two components, which are formed by continuously providing a thick plate portion and a thin plate portion, respectively, and the thin plate portions are connected to each other by the length adjustment mechanism.

8. The test fixture as described in claim 5, characterized in that, At least one of the first vibrating plate, the second vibrating plate, and the third vibrating plate is formed by combining two components, which are formed by continuously providing a thick plate portion and a thin plate portion, respectively, and the thin plate portions are connected to each other by the length adjustment mechanism.

9. The test fixture as described in claim 3, characterized in that, When the effective length of the first vibrating plate is set to L1, the effective length of the second vibrating plate is set to L2, and the effective length of the third vibrating plate is set to L3, L3 = 2(L1 + L2) / 3 holds true.

10. The test fixture as described in claim 4, characterized in that, When the effective length of the first vibrating plate is set to L1, the effective length of the second vibrating plate is set to L2, and the effective length of the third vibrating plate is set to L3, L3 = 2(L1 + L2) / 3 holds true.

11. The test fixture as described in claim 5, characterized in that, When the effective length of the first vibrating plate is set to L1, the effective length of the second vibrating plate is set to L2, and the effective length of the third vibrating plate is set to L3, L3 = 2(L1 + L2) / 3 holds true.

12. A test method, characterized in that, Using the test fixture according to any one of claims 1 to 11, By using the vibration generating device to excite the connection part of the vibration generating device in the z-axis direction, vibrations in directions other than the z-axis direction are applied to the test specimen.

Images