CN116399731A

CN116399731A - Bending fatigue test device and bending fatigue test system

Info

Publication number: CN116399731A
Application number: CN202310235610.9A
Authority: CN
Inventors: 苏鹏程; 王佩艳; 张柯; 赵伟; 霍世慧; 王振
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2023-03-10
Filing date: 2023-03-10
Publication date: 2023-07-07

Abstract

The disclosure relates to the field of fatigue tests, in particular to a bending fatigue test device and a bending fatigue test system. The bending fatigue test device comprises a test bed, a fixed clamp and a loading clamp. The fixed fixture is provided with two limiting ends which are distributed at intervals along the first direction, and the two limiting ends are connected to the test bed. And the fixing clamp can move relative to the test bed along the second direction so as to adjust the distance between the fixing clamp and the test bed. The test bed and the loading clamp are sequentially arranged along the third direction, the loading clamp is movably arranged in the second direction, and the loading clamp is used for driving the test piece to move along the second direction. The first direction is perpendicular to the second direction, and the third direction is perpendicular to both the first direction and the second direction. By implementing the bending fatigue test device and the bending fatigue test system according to the exemplary embodiments of the present disclosure, a cantilever bending fatigue test can be performed on a test piece, and bending fatigue performance of the test piece can be tested.

Description

Bending fatigue test device and bending fatigue test system

Technical Field

The present disclosure relates to the field of fatigue testing, in particular, the method comprises the steps of, relates to a bending fatigue test device and a bending fatigue test system.

Background

Fatigue failure is one of the main causes of engineering structural failure and mechanical failure, and about 50% -90% of structural failure in engineering is caused by fatigue failure, so that the fatigue life of the obtained component is a basic requirement for engineering structure and mechanical part use. Knowing the fatigue strength of the component can predict the useful life of the component and help to determine the safe use and service cycle of the component, thereby ensuring safe use of the component.

Many large complex devices are subject to cantilever bending loads while the components are in a side-to-side condition during use, and it is therefore important to evaluate the fatigue performance of the components by performing cantilever bending fatigue tests.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The present disclosure provides a bending fatigue test device and a bending fatigue test system, which can be used for performing a cantilever bending fatigue test.

According to one aspect of the present disclosure, there is provided a bending fatigue test apparatus comprising:

a test bed;

the fixing clamp is provided with two limiting ends which are distributed at intervals along the first direction, and the two limiting ends are connected to the test bed; the fixed clamp can move relative to the test bed along a second direction so as to adjust the distance between the fixed clamp and the test bed;

the test bench and the loading clamp are sequentially arranged along a third direction, the loading clamp is movably arranged along a second direction, and the loading clamp is used for driving the test piece to move along the second direction;

the first direction is perpendicular to the second direction, and the third direction is perpendicular to both the first direction and the second direction.

In one exemplary embodiment of the present disclosure, each of the limit ends is connected to the test stand by at least two connectors sequentially distributed along the third direction.

In one exemplary embodiment of the present disclosure, the stationary fixture is detachably connected to the test stand by a connection member.

In one exemplary embodiment of the present disclosure, the loading fixture has a first position and a second position when moved in a second direction;

the first position and the second position are respectively positioned at two sides of the test bed along the second direction.

In one exemplary embodiment of the present disclosure, the number of the fixing jigs is equal to the number of the loading jigs, the fixing jigs are distributed in the first direction, and the loading jigs are distributed in the first direction;

each fixing clamp is used for clamping one test piece between the fixing clamp and the test bed; each loading clamp is used for driving one test piece to move along the second direction.

In an exemplary embodiment of the present disclosure, the bending fatigue test apparatus further includes a loading head, the loading clamps are connected to the loading head, the loading head is connected to a power mechanism, and the power mechanism is used for driving the loading head to move along the second direction.

In one exemplary embodiment of the present disclosure, a loading jig includes:

the two ends of the first rolling shaft are rotatably connected with the loading head, and the first rolling shaft extends along a first direction;

the two ends of the second rolling shaft are rotatably connected with the loading head, and the second rolling shaft extends along the first direction;

the first rolling shaft and the second rolling shaft are sequentially arranged along the second direction, and the first rolling shaft and the second rolling shaft drive the test piece clamped between the first rolling shaft and the second rolling shaft to move along the second direction.

In an exemplary embodiment of the present disclosure, the bending fatigue test device further includes:

a displacement acquisition unit for acquiring a distance of the loading head moving along the second direction;

the load acquisition unit is used for acquiring the load of the loading head on the test piece;

and the processing unit is used for generating a displacement-load curve according to the distance of the loading head moving along the second direction and the load of the loading head on the test piece.

a bottom plate;

a vertical support;

an inclined bracket;

wherein, vertical support and the one end fixed connection of oblique support, the other end is connected in the different positions of bottom plate respectively, and the test bench is fixed in vertical support and the one end of oblique support connection.

According to another aspect of the present disclosure, there is provided a bending fatigue test system, comprising:

a power mechanism;

the bending fatigue test device according to any one of the above, which is in driving connection with a power mechanism;

and the test piece is clamped on the bending fatigue test device.

The bending fatigue test device and the bending fatigue test system according to the exemplary embodiments of the present disclosure can be used for performing a cantilever bending fatigue test on a test piece, and testing bending fatigue performance of the test piece. Meanwhile, the degree of freedom of the test piece in the axial direction during bending is relieved, the working condition of pure bending is realized, and the influence of axial force on the bending fatigue test result can be eliminated. Moreover, the loading clamp applies load to one end of the test piece which is not clamped, and a loading point is not required to be fixed, so that a conventional tensile fatigue testing machine can be used, equipment required for completing the test is simpler, the cost can be reduced, and the applicability of the bending fatigue testing device is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort.

For a better understanding of the present disclosure, reference may be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, the relevant elements or components may have different arrangements as known in the art. Furthermore, in the drawings, like reference numerals designate identical or similar parts throughout the several views. Wherein:

FIG. 1 schematically illustrates a structural schematic of a bending fatigue device according to an exemplary embodiment of the present disclosure;

fig. 2 schematically illustrates a structural schematic of a loading jig according to an exemplary embodiment of the present disclosure.

The reference numerals are explained as follows:

1. a test piece; 10. a test bed; 20. a fixing clamp; 30. loading a clamp; 31. a first roller; 32. a second roller; 40. a connecting piece; 50. a loading head; 51. a pull rod; 52. a support rod; 60. a bottom plate; 70. a vertical support; 80. an inclined bracket; 90. a horizontal bracket.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present disclosure. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it is therefore to be understood that various modifications and changes may be made to the example embodiments without departing from the scope of the present disclosure.

Unless specified or indicated otherwise, the terms "coupled," "fixed," and the like are to be construed broadly and are, for example, capable of being coupled either permanently or detachably, or integrally; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present disclosure may be understood by those skilled in the art according to the specific circumstances.

Further, in the description of the present disclosure, it should be understood that the terms "upper", "lower", "left", "right", and the like, as described in the example embodiments of the present disclosure, are merely for convenience, such as described according to the angles shown in the drawings, and should not be construed as limiting the example embodiments of the present disclosure.

The inventors have found that in some cantilever bending fatigue test protocols, clamping of the test piece generally requires fixing one end of the test piece and then loading the other end. However, the test piece is not only subjected to the bending moment, but also to the axial force, so that the test piece is no longer in a purely bending working condition. For some engineering components, such as hose rockers, the structure itself is not subject to axial forces. In the experiment, the influence of the axial force on the test result can lead to inaccurate bending fatigue test result and insufficient reliability of fatigue life prediction of the engineering components.

The present disclosure provides a bending fatigue test device and a bending fatigue test system, which can be used for performing a cantilever bending fatigue test. The bending fatigue test apparatus and the bending fatigue test system of the present disclosure will be described in detail with reference to fig. 1 to 2.

According to one aspect of the present disclosure, there is provided a bending fatigue test apparatus comprising: test stand 10, fixing jig 20, and loading jig 30. The fixing clamp 20 has two limiting ends which are distributed at intervals along the first direction, and the two limiting ends are connected to the test stand 10. And the fixing clamp 20 can move relative to the test stand 10 along the second direction so as to adjust the distance between the fixing clamp 20 and the test stand 10. The test bed 10 and the loading clamp 30 are sequentially arranged along the third direction, the loading clamp 30 is movably arranged along the second direction, and the loading clamp 30 is used for driving the test piece 1 to move along the second direction. The first direction is perpendicular to the second direction, and the third direction is perpendicular to both the first direction and the second direction.

First, for convenience of description and understanding, spatial positional relationship of the structure of the bending fatigue test device of the present disclosure is defined and explained. The first direction, the second direction and the third direction are three directions which are perpendicular to each other in a space. For example, referring to fig. 1, in the space rectangular coordinate system XYZ: the fixing clamp 20 is provided with two limiting ends which are distributed at intervals along the X direction and connected to the test stand 10 through the two limiting ends, and the fixing clamp 20 can move relative to the test stand 10 along the Z direction. The test bed 10 and the loading jig 30 are sequentially disposed in the Y direction, and the loading jig 30 is movable in the Z direction. It should be noted that, unless otherwise specified or indicated, directions such as X direction, Y direction or Z direction in the description of the present disclosure each represent two directions extending along one axis, for example, the test bench 10 and the loading jig 30 are disposed in sequence along the Y direction, and may be a positional relationship as shown in fig. 1, or a positional relationship between the test bench 10 and the loading jig 30, that is, a left side of the loading jig 30 in the direction of the test bench 10.

When the bending fatigue test device of the present disclosure is used for the test, one end of the test piece 1 may be clamped between the fixing jig 20 and the test stand 10, and between the two limit ends in the X direction. The test piece 1 is clamped by the movement of the fixing jig 20 in the Z direction. The loading clamp 30 is used for driving one end of the test piece 1, which is not clamped by the test stand 10 and the fixing clamp 20, to move along the Z direction, so that the test piece 1 is bent, and a bending fatigue test can be performed.

By implementing the bending fatigue test device of the exemplary embodiment of the present disclosure, a bending fatigue test can be performed on the test piece 1, and the bending fatigue performance of the test piece 1 can be tested. The fixing clamp 20 and the test stand 10 limit the movement of the test piece 1 in the Z direction, and the two limiting ends are respectively arranged at two sides of the test piece 1 in the X direction, so that the movement of the limiting ends in the X direction is limited. Therefore, when the other end of the test piece 1 receives the Z-direction load from the loading clamp 30, the test piece 1 can only move in the Y-direction, so that the degree of freedom of the test piece 1 in the Y-direction, namely the degree of freedom in the axial direction when the test piece 1 is bent, the working condition of pure bending is realized, and the influence of the axial force on the bending fatigue test result can be eliminated. Moreover, the loading clamp 30 applies a load to the end of the test piece 1 which is not clamped, so that the end of the test piece 1 which is not clamped moves along the Z direction, and a conventional tensile fatigue testing machine can be used because a loading point is not required to be fixed, so that equipment required for completing the test is simpler, the cost can be reduced, and the applicability of the bending fatigue testing device is improved.

Specifically, the upper surface of the test stand 10, which is in contact with the test piece 1, may be a plane or a curved surface, and may be adaptively adjusted according to the shape of the test piece 1; accordingly, the lower surface of the fixing jig 20 contacting the test piece 1 may also be adapted to the shape of the test piece 1. For example, the upper surface of the test stand 10 and the lower surface of the fixing jig 20 are provided with curved grooves so as to more firmly mount the test piece 1 between the two grooves. In another exemplary embodiment, referring to fig. 1, both the upper surface of the test stand 10 and the lower surface of the fixing jig 20 are flat, and may be used to clamp a flat plate-shaped test piece 1.

Further, in the related art, the tensile or compressive fatigue test cannot be performed in a plastic state for the thin plate-like test piece 1 having a thickness of less than 0.2mm, and thus the thin plate test piece 1 may be tested using the bending fatigue test device of the exemplary embodiment of the present disclosure, and the fatigue performance thereof may be approximately evaluated. The distance between the fixing clamp 20 and the test stand 10 is adjustable, so that test pieces 1 with different thicknesses can be clamped, and the adaptability to the size of the test pieces 1 is improved. The adjustment of the distance between the fixing jig 20 and the test stand 10 may be achieved by means of a threaded connection or a combination of a screw and a nut, etc.

The fixing clamp 20 is connected to the test stand 10 through a limiting end, and specifically, referring to fig. 1, may be detachably connected to the test stand 10 through a connecting member 40 provided at the limiting end. For example, the fixing jig 20 and the test stand 10 are connected by a screw connection. The limiting ends of the fixing clamp 20 are provided with threaded holes, the positions corresponding to the test bed 10 are also provided with threaded holes with consistent thread specifications, when the test piece 1 is installed, the test piece 1 is firstly placed between the positions corresponding to the two limiting ends of the fixing clamp 20 on the test bed 10, then the fixing clamp 20 is aligned with the threaded holes on the test bed 10, and then the test piece 1 is connected through a threaded connecting piece; or pass through the fixing clamp 20 and the light holes on the test stand 10 through the studs, and are locked by nuts on the upper surface of the fixing clamp 20 and the lower surface of the test stand 10. In this case, on the one hand, the disassembly and assembly between the fixing clamp 20 and the test stand 10 are facilitated, and on the other hand, the function of adjusting the distance between the fixing clamp 20 and the test stand 10 can be achieved at the same time, so that the structure is simpler. It will be appreciated by those skilled in the art that the spacing end and the test stand 10 may be connected by riveting, gluing, or other means, which are not particularly limited in this application.

In an exemplary embodiment of the present disclosure, referring to fig. 1, each of the stopper ends is connected to the test stand 10 by at least two connectors 40 sequentially distributed in a third direction. Specifically, the two loading ends are respectively on both sides of the fixing jig 20 in the X direction to restrict the movement of the test piece 1 in the X direction. On the basis, each limiting end is connected to the test stand 10 through at least two connecting pieces 40 distributed along the Y direction, so that the test piece 1 is not easy to move and deflect in the X direction, and the end of the test piece 1 fixed by the fixing clamp 20 and the test stand 10 can only move in the Y direction.

The loading jig 30 moves the test piece 1 in the Z direction, thereby applying a load to the test piece 1. Wherein, the loading clamp 30 clamps the test piece 1 to bend unidirectionally, and changes the magnitude of the load to change the bending moment of the cantilever bending; the loading jig 30 may clamp the test piece 1 to bend in both directions.

For example, in one exemplary embodiment, the loading fixture 30 has a first position and a second position when moving in the Z-direction. The first position and the second position are respectively located at two sides of the test stand 10 along the Z direction. That is, the loading jig 30 drives the test piece 1 to bend bi-directionally, and the loading jig 30 applies an alternating load to the test piece 1 to test the fatigue performance of the test piece 1.

In one exemplary embodiment of the present disclosure, referring to fig. 1, the number of the fixing jigs 20 is equal to the number of the loading jigs 30, the fixing jigs 20 are distributed in the first direction, and the loading jigs 30 are distributed in the first direction. Wherein each fixing jig 20 is used for clamping one test piece 1 between the fixing jig 20 and the test stand 10; each loading fixture 30 is configured to move one test piece 1 in the second direction.

For example, the fixing jigs 20 are distributed along the X direction, the test bed 10 is extended along the X direction, and a plurality of test pieces 1 may be respectively clamped between different fixing jigs 20 and the test bed 10. Each of the fixing jigs 20 is for holding one end of one test piece 1. And at the other end of the test piece 1, a plurality of loading clamps 30 are correspondingly distributed with the fixing clamps 20 along the X direction, and respectively drive the other end of the corresponding test piece 1 to move along the Z direction, so that the test piece 1 is bent.

The bending fatigue test device according to the exemplary embodiment of the present disclosure includes a plurality of fixing jigs 20 and a plurality of loading jigs 30, and thus can test a plurality of test pieces 1 at the same time, and can improve the efficiency of the test.

In an exemplary embodiment of the present disclosure, referring to fig. 1 and 2, the bending fatigue test apparatus further includes a loading head 50, the loading clamps 30 are connected to the loading head 50, the loading head 50 is connected to a power mechanism, and the power mechanism is used to drive the loading head 50 to move along the second direction. The power mechanism drives the loading clamps 30 to move simultaneously through the loading head 50 to load the test pieces 1, so that the same load spectrum can be applied to the test pieces 1 simultaneously, the test efficiency is improved, multiple groups of data are obtained at one time, and the accuracy of results is improved.

In another exemplary embodiment, the loading clamps 30 may also be individually or in groups coupled to the power mechanism, respectively, so that cantilever bending fatigue tests under different test conditions may be performed simultaneously.

The power mechanism may be a tensile fatigue tester or other device capable of providing a vertical load spectrum. Referring to fig. 1 and 2, the power mechanism is connected to the loading head 50, and may be such that a cylindrical pull rod 51 along the Z direction is provided at one end of the loading head 50 away from the loading jig 30, and the other end of the pull rod 51 is clamped by an upper chuck of the tensile testing machine to transmit load to the loading jig 30.

In one exemplary embodiment of the present disclosure, referring to fig. 2, the loading jig 30 includes a first roller 31 and a second roller 32. Both ends of the first roller 31 are rotatably connected to the loading head 50 and extend in a first direction; both ends of the second roller 32 are rotatably connected to the loading head 50, and also extend in the first direction. The first roller 31 and the second roller 32 are sequentially disposed along the second direction, and the first roller 31 and the second roller 32 drive the test piece 1 clamped between the first roller 31 and the second roller 32 to move along the second direction.

Specifically, referring to fig. 2, the first roller 31 and the second roller 32 may be equal in size and aligned in the Z direction. The loading head 50 may include a plurality of support rods 52 extending in the Z direction, and two ends of the first roller 31 and two ends of the second roller 32 are respectively rotatably connected with the loading head 50 through bearings sleeved in the support rods 52. One end of the test piece 1, which is not fixed between the fixing jig 20 and the test stand 10, is clamped between the first roller 31 and the second roller 32.

When the loading head 50 moves in the Z direction, the first roller 31 and the second roller 32 drive the test piece 1 to bend, and meanwhile, as the first roller 31 and the second roller 32 can rotate, the first roller 31 and the second roller 32 do not restrict the degree of freedom of the test piece 1 in the Y direction, and the influence of the axial force of the test piece 1 in the Y direction in the test process is further avoided.

In one exemplary embodiment of the present disclosure, the bending fatigue test apparatus further includes a displacement acquisition unit, a load acquisition unit, and a processing unit. The displacement acquisition unit is used for acquiring the distance of the loading head 50 moving along the second direction; the load acquisition unit is used for acquiring the load of the loading head 50 on the test piece 1; the processing unit is then configured to generate a displacement-load curve based on the distance the loading head 50 moves in the second direction and the load of the loading head 50 on the test piece 1.

Wherein the displacement acquisition unit and the load acquisition unit may be displacement sensors and force sensors, and the processing unit may be a processor including a data calculation function, an electronic computer preset with a program for drawing according to the acquired data, and the like. Of course, the displacement acquiring unit, the load acquiring unit and the processing unit are merely descriptions of functions, and the actual structures thereof may be separate or integrated into the same entity, for example, may be partially or fully integrated into the power mechanism, which is not particularly limited in the present disclosure.

The strain response of the material to the load is different when facing test piece 1 of different material. For example, when a strain softening material such as plastic, concrete or the like is loaded, the strain reaches a maximum value, and the continuous loading does not cause great change of the stress, so that the test piece 1 is easy to break suddenly. Specifically, taking fig. 1 as an example, in the process that the loading head 50 moves downwards under the drive of the power mechanism, after the load of the loading head 50 on the test piece 1 reaches a certain value at a certain position, the load is difficult to continue to increase, and at the moment, the deformation amount of the test piece 1 continues to increase. Therefore, it is necessary to adopt a displacement-controlled loading method and generate a displacement-load curve of the test piece 1, so that the bending fatigue performance of the material can be more comprehensively reflected.

In an exemplary embodiment, the power mechanism such as a tensile fatigue testing machine has at least a displacement-controlled loading mode and a stress-controlled loading mode, and the displacement amount of the loading head 50 per unit time, or the load increase amount of the loading head 50 per unit time on the test piece 1 can be controlled. And can be switched between different modes.

In one exemplary embodiment of the present disclosure, referring to fig. 1, the bending fatigue test apparatus further includes a base plate 60, a vertical support 70, and an inclined support 80. Wherein, one end of the vertical support 70 and one end of the inclined support 80 are fixedly connected, the other end is respectively connected with different positions of the bottom plate 60, and the test stand 10 is fixed at one end of the vertical support 70 connected with the inclined support 80. The vertical brackets 70, the diagonal brackets 80 and the bottom plate 60 thus form a triangular structure with good rigidity. In another exemplary embodiment, referring to fig. 1, two ends of the test stand 10 are respectively fixed to the connection ends of two sets of vertical brackets 70 and diagonal brackets 80, forming two sets of triangular stable supports. When the cantilever bending fatigue test is carried out, the whole test device is stable, the shaking does not occur, and the influence of danger or slight shaking on the test result in the test process is prevented. The two sets of brackets may be further reinforced by horizontal brackets 90. The horizontal bracket 90 may be connected between the two vertical brackets 70.

According to another aspect of the present disclosure, there is provided a bending fatigue test system including a bending fatigue test device, a power mechanism, and a test piece 1, the bending fatigue test device being drivingly connected to the power mechanism, the test piece 1 being clamped to the bending fatigue test device. The specific implementation of the bending fatigue device has been described in detail in the foregoing exemplary embodiments, and will not be described herein. The power mechanism can be a tensile fatigue testing machine or other devices capable of providing a vertical load spectrum and can provide a test load with certain frequency and stress ratio. The test piece 1 may be specifically a bar-shaped or plate-shaped test piece 1, for example, referring to fig. 1, the test piece 1 is a thin plate shape having a thickness of less than 0.2mm, one end clamped to the test stand 10 and the fixing jig 20 may be different in width from one end clamped to the loading jig 30, and the material of the test piece 1 may be replaced according to the requirements of specific tests.

By implementing the bending fatigue test system of the exemplary embodiment of the present disclosure, a bending fatigue test can be performed to test the bending fatigue performance of the test piece 1. And the axial freedom degree of the test piece 1 during bending is liberated, the pure bending working condition is realized, and the influence of the axial force on the bending fatigue test result can be eliminated. The power mechanism can be a conventional tensile fatigue testing machine, equipment required for completing the test is simpler, the cost can be reduced, and the applicability of the bending fatigue testing device is improved.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any adaptations, uses, or adaptations of the disclosure following the general principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A bending fatigue test device, comprising:

a test bed;

the test bench and the loading clamp are sequentially arranged along a third direction, the loading clamp is movably arranged along the second direction, and the loading clamp is used for driving the test piece to move along the second direction;

2. The bending fatigue test device according to claim 1, wherein each of the limit ends is connected to the test bed by at least two connecting pieces distributed in sequence along the third direction.

3. The bending fatigue test device according to claim 2, wherein the fixing jig is detachably connected to the test stand through the connection member.

4. The bending fatigue test device of claim 1, wherein the loading clamp has a first position and a second position when moved in the second direction;

5. The bending fatigue testing device according to any one of claims 1 to 4, wherein the number of the fixing jigs and the loading jigs are equal, the fixing jigs being distributed along the first direction, the loading jigs being distributed along the first direction;

wherein each fixing clamp is used for clamping one test piece between the fixing clamp and the test bench; each loading clamp is used for driving one test piece to move along the second direction.

6. The bending fatigue testing device according to claim 5, further comprising a loading head, wherein the loading clamps are connected to the loading head, and wherein the loading head is connected to a power mechanism for driving the loading head to move in the second direction.

7. The bending fatigue test device according to claim 6, wherein the loading jig comprises:

the two ends of the first rolling shaft are rotatably connected with the loading head, and the first rolling shaft extends along the first direction;

8. The bending fatigue test apparatus according to claim 6, wherein the bending fatigue test apparatus further comprises:

a load acquisition unit for acquiring a load of the loading head on the test piece;

9. The bending fatigue test device according to claim 1, wherein the bending fatigue test device further comprises:

a bottom plate;

a vertical support;

an inclined bracket;

the test bed is fixed at one end of the vertical support, which is connected with the inclined support.

10. A bending fatigue test system, comprising:

a power mechanism;

the bending fatigue testing device according to any one of claims 1 to 9, drivingly connected to the power mechanism;

and the test piece is clamped on the bending fatigue test device.