High temperature composite compression fixture for testing machine

Abstract

The utility model relates to a testing machine, especially to high temperature composite material compression clamp for testing machine, the upper clamping block group clamps the upper end of sample, the lower clamping block group clamps the lower end of sample, the sample axial verticality in initial state, through the orientation between the upper clamping block group and the lower clamping block group in vertical direction, and then in the compression test, the axial verticality of force is guaranteed to sample, and the consistency of test result is guaranteed.

Description

Technical Field

[0001] This utility model relates to testing machines, and more particularly to high-temperature composite material compression clamps for testing machines. Background Technology

[0002] High-temperature composite materials, such as fiber-reinforced composites (FRCs), are widely used in aerospace, automotive, construction, and energy fields due to their superior mechanical properties, lightweight nature, and corrosion resistance. Fiber-reinforced composites consist of two parts: fibers and a matrix. The fibers provide the primary load-bearing capacity, while the matrix binds the fibers together, transfers loads, and protects the fibers from environmental influences. This composite structure gives the material excellent strength and stiffness in the tensile direction. In practical applications, fiber-reinforced composites often need to withstand complex stress states, including tension, compression, shear, and bending. Therefore, understanding the material's performance under various loading conditions is crucial for structural design and safety assessment. Especially for critical components subjected to high compressive loads, such as aerospace wings and fuselages, and automotive structural components, the compressive properties of the material directly affect the safety and reliability of the structure.

[0003] There are three main loading methods for composite material compression tests: 1. end loading; 2. shear loading; 3. combined loading. Combined loading uses specially designed fixtures to introduce loads from the ends and shear points, which can reduce stress concentration and minimize defects caused by end loading and shear loading in compression tests, ensuring the consistency of test results. For combined loading, two key aspects need to be considered: first, how to ensure the flatness and parallelism of the compression plate when introducing end loads to ensure uniform load transfer at the ends of the specimen; and second, whether the specimen is axially vertical to prevent specimen tilting or buckling. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-temperature composite material compression clamp for testing machines that can ensure the verticality of the sample axis.

[0005] This utility model is achieved through the following technical solution: a high-temperature composite material compression fixture for a testing machine, comprising an upper clamping block group and a lower clamping block group, wherein a guide structure is provided between the upper clamping block group and the lower clamping block group, and the guide structure guides the upper clamping block group and the lower clamping block group in the vertical direction.

[0006] Furthermore, the guide structure includes a guide post disposed between the upper clamping block group and the lower clamping block group.

[0007] Furthermore, the upper clamping block assembly includes an upper left clamping block and an upper right clamping block, and an upper locking structure is provided between the upper left clamping block and the upper right clamping block. The upper locking structure can control the distance between the upper left clamping block and the upper right clamping block.

[0008] Furthermore, an upper transverse guide structure is provided between the upper left clamping block and the upper right clamping block.

[0009] Furthermore, the upper clamping block assembly also includes an upper positioning plate, which extends into the gap between the upper left clamping block and the upper right clamping block.

[0010] Furthermore, the lower clamping block assembly includes a lower left clamping block and a lower right clamping block, and a lower locking structure is provided between the lower left clamping block and the lower right clamping block. The lower locking structure can control the distance between the lower left clamping block and the lower right clamping block.

[0011] Furthermore, a lower lateral guide structure is provided between the lower left clamping block and the lower right clamping block.

[0012] Furthermore, the lower clamping block assembly also includes a lower positioning plate, and the upper positioning plate extends into the gap between the lower left clamping block and the lower right clamping block.

[0013] The beneficial effects of this utility model are as follows: the upper clamping block group clamps the upper end of the sample and the lower clamping block group clamps the lower end of the sample. In the initial state, the sample is axially vertical. The guide structure guides the upper clamping block group and the lower clamping block group in the vertical direction, thereby ensuring that the sample is subjected to axial vertical force during the compression test and ensuring the consistency of the test results. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of Example 1;

[0015] Figure 2 This is a schematic diagram of another orientation of the structure in Example 1;

[0016] Figure 3 A schematic diagram of the guide structure cross-section;

[0017] Figure 4 This is a schematic cross-sectional view of the upper and lower transverse guide structures.

[0018] The components are: 1. Upper left clamping block; 2. Upper right clamping block; 3. Upper positioning plate; 4. Locking bolt; 5. Lower left clamping block; 6. Lower right clamping block; 7. Lower positioning plate; 8. Sample; 9. Positioning groove; 10. Guide sleeve; 11. Guide post; 12. Operating port; 13. Snap ring; 14. Upper guide pin; 15. Lower guide pin. Detailed Implementation

[0019] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0021] Example 1

[0022] like Figure 1-4 As shown, a high-temperature composite material compression fixture for testing machines is used for experiments on high-temperature composite materials, such as fiber composite materials. It includes an upper clamping block group and a lower clamping block group. The upper clamping block group includes an upper left clamping block 1 and an upper right clamping block 2, and the lower clamping block group includes a lower left clamping block 5 and a lower right clamping block 6. The upper left clamping block 1, upper right clamping block 2, lower left clamping block 5, and lower right clamping block 6 are all made of aluminum alloy, which has high structural strength. In some embodiments, the weight can be reduced by machining process holes. Anti-slip textures are machined on the working surfaces of the upper left clamping block 1, upper right clamping block 2, lower left clamping block 5, and lower right clamping block 6 to improve the friction between them and the sample 8.

[0023] An upper locking structure is installed between the upper left clamping block 1 and the upper right clamping block 2. The upper locking structure can control the distance between the upper left clamping block 1 and the upper right clamping block 2. A lower locking structure is installed between the lower left clamping block 5 and the lower right clamping block 6. The lower locking structure can control the distance between the lower left clamping block 5 and the lower right clamping block 6. Specifically, both the upper and lower locking structures use locking bolts 4, which are semi-threaded bolts. The upper left clamping block 1 and the lower left clamping block 5 are machined with smooth holes that mate with the corresponding semi-threaded bolts. The smooth holes are through holes. The upper right clamping block 2 and the lower right clamping block 6 are machined with threaded holes that mate with the corresponding semi-threaded bolts. The threaded holes are blind holes or through holes. The semi-threaded bolts pass through the smooth holes and connect with the threaded holes for easy operation.

[0024] An upper transverse guide structure is installed between the upper left clamping block 1 and the upper right clamping block 2, and a lower transverse guide structure is installed between the lower left clamping block 5 and the lower right clamping block 6. Specifically, the upper transverse guide structure includes an upper guide pin 14 installed between the upper left clamping block 1 and the upper right clamping block 2. The upper end faces of the upper left clamping block 1 and the upper right clamping block 2 are coplanar. The upper guide pin 14 ensures that the upper end faces do not rotate relative to each other during the relative movement of the lower left clamping block 5 and the lower right clamping block 6. The lower transverse guide structure includes a lower guide pin 15 installed between the lower left clamping block 5 and the lower right clamping block 6. The upper end faces of the lower left clamping block 5 and the lower right clamping block 6 are coplanar. The lower guide pin 15 ensures that the lower end faces do not rotate relative to each other during the relative movement of the lower left clamping block 5 and the lower right clamping block 6.

[0025] A guide structure is installed between the upper clamping block assembly and the lower clamping block assembly. The guide structure guides the upper and lower clamping block assemblies vertically. Specifically, the guide structure includes positioning grooves 9 machined on the upper left clamping block 1 and the upper right clamping block 2. A guide sleeve 10 is installed in the positioning groove 9. The guide sleeve 10 is a copper sleeve, and the guide sleeve 10 is interference-fitted with the positioning groove 9. A retaining spring 13 is also installed at the upper end of the positioning groove 9 to block the guide sleeve 10. The retaining spring 13 is an internal retainer. Spring 13 and positioning groove 9 are stepped grooves to prevent the copper sleeve from disengaging downward from the corresponding upper left clamping block 1 and upper right clamping block 2. Guide post 11 is installed inside guide sleeve 10. Guide post 11 is a stainless steel post. The lower end of guide post 11 is interference-fitted to the corresponding lower left clamping block 5 and lower right clamping block 6, so that upper left clamping block 1 and upper right clamping block 2 can move synchronously in the vertical direction. During compression test, it is ensured that sample 8 is subjected to axial vertical force to ensure the consistency of test results.

[0026] The upper clamping block assembly also includes an upper positioning plate 3, which extends into the gap between the upper left clamping block 1 and the upper right clamping block 2. The upper positioning plate 3 has an L-shaped cross-section. The first wing of the upper positioning plate 3 is attached to the side wall of the upper left clamping block 1 or the upper right clamping block 2 and fixed with bolts. The second wing of the upper positioning plate 3 extends into the gap between the upper left clamping block 1 and the upper right clamping block 2. The lower clamping block assembly also includes a lower positioning plate 7, which extends into the gap between the lower left clamping block 5 and the lower right clamping block 6. The lower positioning plate 7 has an L-shaped cross-section. The first wing of the lower positioning plate 7 is attached to the side wall of the lower left clamping block 5 or the lower right clamping block 6 and fixed with bolts. The second wing of the lower positioning plate 7 extends into the gap between the lower left clamping block 5 and the lower right clamping block 6. The vertical end face of the second wing of the upper positioning plate 3 is coplanar with the vertical end face of the second wing of the lower positioning plate 7, forming a side support surface for supporting the sample 8, thereby simultaneously supporting the sample 8.

[0027] An operating port 12 is also machined at the middle position of the upper left clamping block 1, upper right clamping block 2, lower left clamping block 5 and lower right clamping block 6, so as to facilitate the adjustment of the position of the sample 8 in the initial stage.

[0028] The high-temperature composite material compression fixture for the testing machine provided in this embodiment, during the installation of sample 8, first loosens the locking bolt 4, adjusts the position of sample 8 so that sample 8 fits against the side support surface, then tightens the locking bolt 4 to clamp sample 8, and then places it on the testing machine. The upper clamping block group and the lower clamping block group move relative to each other in the vertical direction, and the surfaces that mate with the testing machine do not deform, ensuring that sample 8 is axially vertical, thus resulting in high consistency of test results. When selecting a testing machine, a testing machine with uniform force distribution on the upper and lower pressure plates should be selected to reduce the deviation of test results caused by the structure of the testing machine itself.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high temperature composite compression fixture for a test machine, characterized by, It includes an upper clamping block group and a lower clamping block group. A guide structure is provided between the upper clamping block group and the lower clamping block group. The guide structure guides the upper clamping block group and the lower clamping block group in the vertical direction. The upper clamping block group includes an upper left clamping block and an upper right clamping block. An upper locking structure is provided between the upper left clamping block and the upper right clamping block. The upper locking structure can control the distance between the upper left clamping block and the upper right clamping block.

2. The high temperature composite compression fixture for a test machine of claim 1, wherein, The guide structure includes a guide post disposed between the upper clamping block group and the lower clamping block group.

3. The high temperature composite compression fixture for a test machine of claim 1, wherein, An upper transverse guide structure is provided between the upper left clamping block and the upper right clamping block.

4. The high temperature composite compression fixture for a test machine of claim 1, wherein, The upper clamping block assembly also includes an upper positioning plate, which extends into the gap between the upper left clamping block and the upper right clamping block.

5. The high temperature composite compression fixture for a test machine of claim 4, wherein, The lower clamping block assembly includes a lower left clamping block and a lower right clamping block. A lower locking structure is provided between the lower left clamping block and the lower right clamping block, and the distance between the lower left clamping block and the lower right clamping block can be controlled by the lower locking structure.

6. The high-temperature composite material compression fixture for a testing machine according to claim 5, characterized in that, A lower lateral guide structure is provided between the lower left clamping block and the lower right clamping block.

7. The high temperature composite compression fixture for a test machine of claim 5, wherein, The lower clamping block assembly also includes a lower positioning plate, and the upper positioning plate extends into the gap between the lower left clamping block and the lower right clamping block.

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