Prestress-adjustable compression test fixture

Abstract

The utility model discloses a compression test fixture with adjustable prestress, which belongs to the field of material test devices and comprises a steel frame, an upper seat body clamping plate, a lower seat body clamping groove, a left seat body and a right seat body clamping plate are arranged in the steel frame, and the left seat body clamping plate and the right seat body clamping plate are symmetrically arranged in the steel frame. By adopting the structure, the compression test fixture with the adjustable prestress is used for clamping a composite material test piece to be compressed, the threaded rod is mutually matched with the groove of the bottom bracket, and the prestress is applied to the test piece by manually twisting the threaded rod in a manner that one end is fixed and the other end moves in a single direction; the limit compression strength of the test piece under the condition that the test piece bears prestress can be obtained through testing, meanwhile, the prestress of different sizes can be set by adjusting the number of rotation turns, and the limit compression strength of the composite material flat plate can be more accurately tested.

Description

Technical Field

[0001] The utility model relates to the technical field of material testing devices, in particular to a compression testing fixture with adjustable prestress. Background Art

[0002] In the field of new energy vehicles, on-board hydrogen storage cylinders, as key energy supply devices for hydrogen-powered vehicles, have been widely used due to their simple structure and high reliability. In recent years, composite materials have been widely used in on-board hydrogen storage cylinders due to their high specific strength, high specific stiffness, and light weight. In the normal service of new energy vehicles, collision accidents are inevitable. As the main load-bearing structure of the vehicle, it is necessary to consider whether the cylinder can withstand the axial compression load generated by the collision of the vehicle. Therefore, before the composite materials are applied to hydrogen storage cylinders for hydrogen-powered vehicles, compression tests should be carried out on the composite test pieces to assess the compression performance of the composite materials of this model. However, during the daily use of composite hydrogen storage cylinders, due to the presence of internal hydrogen, the composite hydrogen storage cylinders will be subjected to a certain prestress, and the presence of this prestress will have a certain effect on the compression strength of the composite materials.

[0003] The influence of prestress on compression test is not considered in the current composite material compression test standard. However, the existence of prestress is an important factor that must be taken into account in order to obtain the ultimate axial compressive strength of composite hydrogen storage cylinders in the actual service environment. Utility Model Content

[0004] The purpose of the utility model is to provide a compression test fixture with adjustable prestress, which is used to clamp a composite material specimen to be compressed. The threaded rod and the groove of the bottom bracket cooperate with each other, and the prestress is applied to the specimen by artificially twisting the threaded rod in a way that one end is fixed and the other end moves in one direction, so that the ultimate compression strength of the specimen under the condition of prestress can be obtained. At the same time, by adjusting the number of rotations and setting different sizes of prestress, a more accurate ultimate compression strength test of a composite material flat plate can be performed.

[0005] To achieve the above-mentioned purpose, the utility model provides an adjustable prestressed compression test fixture, including a steel frame, wherein an upper seat body clamping plate, a lower seat body clamping groove, a left seat body clamping plate and a right seat body clamping plate are arranged inside the steel frame, and the left seat body clamping plate and the right seat body clamping plate are symmetrically arranged in the steel frame.

[0006] Preferably, the upper seat body clamping plate comprises an upper seat body front clamping plate and an upper seat body rear concave plate, and the upper seat body front clamping plate and the upper seat body rear concave plate are connected by bolts.

[0007] Preferably, the lower seat body clamping groove includes a lower seat body front clamping block and a lower seat body rear clamping block which are arranged in the same plane as the lower plane of the steel frame and have a gap therebetween.

[0008] Preferably, the left seat body clamping plate includes a pushing structure and a left extrusion plate, and the right seat body clamping plate includes a right extrusion plate and a support plate. The left extrusion plate and the right extrusion plate have the same structure and are symmetrically arranged.

[0009] Preferably, the pushing structure includes a screw rod, which horizontally passes through the steel frame and is connected to the left extrusion plate through a sleeve.

[0010] Preferably, the support plate is vertically arranged, the bottom surface of the support plate is connected to the steel frame, and the side surface of the support plate is connected to the right extrusion plate.

[0011] Preferably, the left extrusion plate includes two parallel left clamping blocks and a left bottom plate, the close surfaces of the two left clamping blocks are set as conical surfaces, a number of long through holes are evenly arranged on the two left clamping blocks and the left bottom plate, and the two left clamping blocks are connected to the left bottom plate through the long through holes using bolts.

[0012] Preferably, the right extrusion plate includes two parallel right clamping blocks and a right bottom plate, the close surfaces of the two right clamping blocks are set as conical surfaces, a number of long through holes are evenly arranged on the two right clamping blocks and the right bottom plate, and the two right clamping blocks are connected to the right bottom plate using bolts through the long through holes.

[0013] Therefore, the utility model adopts an adjustable prestressed compression test fixture of the above structure, which has the following beneficial effects:

[0014] (1) In the utility model, the structural scheme designed is based on meeting the ASTM international standard. By expanding the post-impact compression fixture and adding a prestressing frame, the screw rod, the steel frame and the seat bodies in different directions cooperate with each other to realize the compression strength test of the composite material under different sizes of prestress.

[0015] (2) In the utility model, clamping plates are provided in the left extrusion plate and the right extrusion plate, and a gap is provided between the two plates of the lower seat body. The distance between the two clamping blocks is adjusted by moving the bolt in the horizontal long through hole, and the conical surface is used to lock the specimen, so that the specimens of different thicknesses are clamped and fixed, thereby achieving the purpose of stably clamping composite material specimens of different thicknesses.

[0016] (3) In the present invention, the clamp of the present invention can prevent the right seat body clamp from tipping over by arranging a triangular supporting side plate on the outer side of the right seat body clamp, thereby achieving a better supporting and fixing effect.

[0017] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural schematic diagram of a compression test fixture with adjustable prestress of the utility model;

[0019] Figure 2 This is a structural explosion diagram of a compression test fixture with adjustable prestress of the utility model;

[0020] Reference numerals:

[0021] 1. Front clamping plate of upper seat body; 2. Rear concave plate of upper seat body; 3. Steel frame; 4. Rear clamping block of lower seat body; 5. Front clamping block of lower seat body; 6. Left seat body clamping plate; 7. Right seat body clamping plate; 8. Screw; 9. Sleeve; 10. Bottom plate; 11. Clamping block; 12. Support plate. DETAILED DESCRIPTION

[0022] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.

[0023] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] Example

[0025] like Figure 1-2The utility model provides an adjustable prestressed compression test fixture, including a steel frame 3, wherein an upper seat body clamping plate, a lower seat body clamping groove, a left seat body clamping plate 6 and a right seat body clamping plate 7 are arranged inside the steel frame 3, the steel frame 3 fixes the internal structure, and the internal structure fixes and applies prestress to the test piece, the upper seat body clamping plate includes an upper seat body front clamping plate 1 and an upper seat body rear concave plate 2, and the upper seat body front clamping plate 1 and the upper seat body rear concave plate 2 are connected by bolts; the upper seat body clamping plate can be fixed to the upper end of the test piece, and in subsequent compression tests, the contact surface of the pressure application is expanded to avoid the buckling of the plate caused by uneven pressure application, and the lower seat body clamping groove includes a steel frame 3 and a lower seat body clamping plate 6 and a lower seat body clamping plate 7. The lower plane of the frame 3 is arranged in the same plane and has a gap between the front clamping block 5 and the rear clamping block 4 of the lower seat body. The front clamping block 5 and the rear clamping block 4 of the lower seat body are arranged in the same plane, which does not hinder the clamping effect of other structures on the specimen and does not affect the application of prestress. A gap is arranged between the front clamping block 5 and the rear clamping block 4 of the lower seat body. The gap is used to clamp the bottom of the specimen and keep the specimen in a vertical upward state. The left seat body clamping plate 6 and the right seat body clamping plate 7 are symmetrically arranged in the steel frame 3, and can clamp the specimen from both sides for fixing. The left seat body clamping plate 6 includes a pushing structure and a left extrusion plate. The pushing structure includes a screw 8, and the screw 8 It passes horizontally through the steel frame 3 and is connected to the left extrusion plate through the sleeve 9. The screw 8 is used to push or pull back the left extrusion plate. After the specimen is fixed, the screw 8 is rotated to push the left extrusion plate to apply prestress to the specimen. The right seat clamp 7 includes a right extrusion plate and a support plate 12. The support plate 12 is vertically arranged. The bottom surface of the support plate 12 is connected to the steel frame 3. The side surface of the support plate 12 is connected to the right extrusion plate. The left extrusion plate and the right extrusion plate have the same structure and are symmetrically arranged. The left extrusion plate includes two parallel left clamping blocks 11 and a bottom plate 10. The surfaces close to the two left clamping blocks 11 are set as conical surfaces. The conical surfaces are used to bite the specimen. A plurality of long through holes are evenly arranged on the clamping block 11 and the left bottom plate 10, and the two left clamping blocks 11 are connected to the left bottom plate 10 by bolts through the long through holes. The right extrusion plate includes two parallel right clamping blocks 11 and the right bottom plate 11, and the close surfaces of the two right clamping blocks 11 are set as conical surfaces. A plurality of long through holes are evenly arranged on the two right clamping blocks 11 and the right bottom plate 10, and the two right clamping blocks 11 are connected to the right bottom plate 10 by bolts through the long through holes. Through the long through holes, after loosening the bolts, the horizontal spacing between the two clamping blocks 11 can be adjusted, thereby changing the width of the corresponding clamped specimen, and has good adaptability to specimens of different widths.

[0026] During the specific experiment, when using, first place the flat plate specimen of specified thickness in the middle gap between the front clamp block of the lower seat body and the rear clamp block of the lower seat body, so that the specimen can maintain a vertical upward state, and place the specimen close to the right extrusion plate in the right seat body clamp, adjust the position of the two right clamp blocks in the right extrusion plate, use the conical surface of the right clamp block to clamp the specimen, and fix the right clamp block to the bottom plate with bolts. The fixed right clamp block fixes the specimen, and a support plate is set in the right extrusion plate. The support plate can fix the relative position relationship between the right extrusion block and the steel frame to prevent the specimen from tipping over while achieving the fixation of the right edge of the specimen. When using the clamp block, in order to enhance the friction force on the surface of the specimen, the contact surface between the clamp block and the specimen needs to be processed by embossing technology, which can effectively increase friction and prevent the specimen from falling off. Use a screw to adjust the horizontal position of the left extrusion plate so that the two left clamp blocks of the left extrusion plate are fixed on the left side of the specimen, adjust the horizontal interval of the two left clamp blocks, clamp the specimen and fix it with bolts The left edge of the specimen is fixed with the left extrusion plate, and then the screw is connected to the left extrusion plate through the sleeve, and the sleeve is fixed on the left extrusion plate with a screw, and the screw is fixed by the sleeve. The screw rotates and moves back and forth to realize the horizontal back and forth movement of the left extrusion plate. In order to facilitate the rotation, an auxiliary handle is provided on the top of the screw to facilitate the rotation. The front splint of the upper seat body and the rear concave plate of the upper seat body are placed parallel to the upper surface of the specimen, and the front splint of the upper seat body and the rear concave plate of the upper seat body are connected with bolts, and the upper seat body splint is fixed to the upper layer of the specimen to complete the clamping work of the compression test fixture on the specimen. The compression test fixture is placed on the experimental table of the universal testing machine, and the prestress can be applied to the left clamping body as a whole by continuing to rotate the screw. Since the left clamping seat body splint is in a state of clamping the flat plate specimen at this time, there is a large friction between the two, so the prestress will be transmitted to the flat plate specimen. At this time, starting the universal testing machine can complete the compression test of the prestressed flat plate material.

[0027] Therefore, the utility model adopts an adjustable prestressed compression test fixture of the above structure, which is used to clamp the composite material test piece. Through the mutual cooperation of the threaded rod and the groove of the bottom bracket, the test piece is prestressed by manually twisting the threaded rod in a way that one end is fixed and the other end moves in one direction, and the ultimate compression strength of the test piece under the condition of prestress can be obtained. At the same time, by adjusting the number of rotations of the screw rod, different sizes of prestress can be adjusted, and more accurate composite plate ultimate compression strength tests can be performed.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.

Claims

1. A compression test fixture with adjustable prestress, characterized in that: It comprises a steel frame, wherein an upper seat body clamping plate, a lower seat body clamping groove, a left seat body clamping plate and a right seat body clamping plate are arranged inside the steel frame, and the left seat body clamping plate and the right seat body clamping plate are symmetrically arranged in the steel frame.

2. The adjustable prestressed compression test fixture according to claim 1, characterized in that: The upper seat body clamping plate comprises an upper seat body front clamping plate and an upper seat body rear concave plate, and the upper seat body front clamping plate and the upper seat body rear concave plate are connected by bolts.

3. The adjustable prestressed compression test fixture according to claim 2, characterized in that: The lower seat body clamping groove comprises a lower seat body front clamping block and a lower seat body rear clamping block which are arranged in the same plane as the lower plane of the steel frame and have a gap therebetween.

4. The adjustable prestressed compression test fixture according to claim 3, characterized in that: The left seat body clamping plate includes a pushing structure and a left extrusion plate, and the right seat body clamping plate includes a right extrusion plate and a supporting plate. The left extrusion plate and the right extrusion plate have the same structure and are symmetrically arranged.

5. The adjustable prestressed compression test fixture according to claim 4, characterized in that: The pushing structure includes a screw rod, which horizontally passes through the steel frame and is connected to the left extrusion plate through a sleeve.

6. The adjustable prestressed compression test fixture according to claim 5, characterized in that: The support plate is vertically arranged, the bottom surface of the support plate is connected to the steel frame, and the side surface of the support plate is connected to the right extrusion plate.

7. The adjustable prestressed compression test fixture according to claim 6, characterized in that: The left extrusion plate includes two parallel left clamping blocks and a left bottom plate, the close surfaces of the two left clamping blocks are set as conical surfaces, a number of long through holes are evenly arranged on the two left clamping blocks and the left bottom plate, and the two left clamping blocks are connected to the left bottom plate using bolts through the long through holes.

8. The adjustable prestressed compression test fixture according to claim 7, characterized in that: The right extrusion plate includes two parallel right clamping blocks and a right bottom plate, the close surfaces of the two right clamping blocks are set as conical surfaces, a number of long through holes are evenly arranged on the two right clamping blocks and the right bottom plate, and the two right clamping blocks are connected to the right bottom plate using bolts through the long through holes.

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