A tensile test fixture for carbon fiber copper composite

Abstract

The utility model belongs to the field of composite material mechanics performance test, especially relate to a kind of tensile test fixture of carbon fiber copper composite material.The technology includes two vertically arranged bases, two bases are symmetrically distributed with interval, two bases are detachably installed with pressing plate on each, the face of each base and corresponding pressing plate is attached is mounting surface;Two bases are provided with wedge slot on mounting surface, each wedge slot is provided with wedge block in sliding fit;Two wedge blocks are symmetrically arranged;The face of each wedge block towards corresponding pressing plate is protruded from mounting surface;Reset component is provided on each base.During tensile test, material sample will exert friction on wedge block, so that wedge block generates sliding tendency in wedge slot, by the mechanical properties of inclined plane, part of force is converted into extrusion force of wedge block on material sample, so that material sample is not easy to slip between fixture in tensile property test.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical property testing of composite materials, and in particular relates to a tensile test fixture for carbon fiber copper composite materials. Background Technology

[0002] Carbon fiber reinforced copper matrix composites are materials with copper as the matrix and carbon fiber as the reinforcement. They combine the electrical and thermal conductivity of copper with the wear resistance of carbon fiber and have wide applications. Since the mechanical properties of materials are crucial to the reliability of practical engineering projects, and tensile property testing can determine key parameters such as strength and elastic modulus, providing a basis for design, such testing is necessary.

[0003] Through literature review and actual experimental testing, it was found that current tensile property testing commonly uses the universal fixtures integrated into electronic universal testing machines. While these fixtures are compatible with a wide range of materials and sizes, they are prone to slippage during tensile testing due to variations in the surface properties of composite materials. This phenomenon makes it difficult to conduct accurate and stable testing of the mechanical properties of composite materials, thus affecting the reliability and validity of the experimental data. Utility Model Content

[0004] The purpose of this invention is to provide a tensile testing fixture for carbon fiber copper composite materials, which prevents slippage between the composite material and the fixture during tensile performance testing.

[0005] The tensile test fixture for the carbon fiber copper composite material includes two vertically arranged bases, which are symmetrically distributed at an interval. Each base has a detachable and parallel pressure plate mounted on it. The side of each base that contacts the corresponding pressure plate is the mounting surface. Wedge-shaped grooves are formed on the mounting surfaces of the two bases, and each groove contains a wedge block that slides within it. The two wedge blocks are symmetrically arranged. The side of each wedge block facing the corresponding pressure plate protrudes from the mounting surface, used to pre-tighten the material sample in conjunction with the corresponding pressure plate. Each base is equipped with a reset component for resetting the moved wedge blocks.

[0006] Furthermore, the reset assembly includes a spring, and a baffle is detachably mounted on the side wall of the base facing the middle section of the material sample, with the spring installed between the baffle and the wedge block.

[0007] Furthermore, each pressure plate has a groove on its mounting surface for limiting the material sample. The bottom surface of the groove and the surface where the wedge block contacts the material sample are rough surfaces.

[0008] Furthermore, several positioning blocks are fixed on the mounting surface of the pressure plate, and several positioning grooves for independently engaging the positioning blocks are provided on the mounting surface of the base corresponding to all the positioning blocks.

[0009] Furthermore, each positioning block has a chamfer at the corner facing the positioning groove.

[0010] Furthermore, each base is provided with connection holes for connecting to the working end of the universal testing machine.

[0011] Furthermore, the two walls of the wedge-shaped groove are provided with mutually symmetrical sliding grooves, the two sliding grooves are parallel to the bottom of the wedge-shaped groove, and the two side walls of the wedge block are fixed with sliders that can slide along the corresponding sliding grooves.

[0012] Compared with the prior art, the present invention has the following beneficial effects: During tensile testing, the material specimen applies frictional force to the wedge block, causing the wedge block to tend to slip within the wedge groove. Utilizing the mechanical properties of the inclined plane, a portion of this force is converted into a compressive force exerted by the wedge block on the material specimen. This conversion process significantly increases the contact pressure between the wedge block and the material specimen, thereby enhancing the frictional force between them. This increasing pressure effectively reduces the probability of slippage during tensile testing, making it less likely for the material specimen to slip between itself and the clamps. This ensures that the material specimen is securely clamped throughout the tensile testing process, guaranteeing the accuracy and stability of the material specimen's mechanical property measurements.

[0013] After the tensile performance test is completed, the spring will push the wedge block to move and reset to its initial state through its own restoring characteristics, so that it can be used directly in the next test. This reduces the number of steps for staff to move and adjust the position of the wedge block, reduces the workload of staff, and makes the operation process simpler and more convenient. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 Sectional view at point AA; Figure 3 This is a perspective view of the present utility model; Figure 4 This is an exploded view of the present invention; The components in the diagram are named as follows: 1. Pressure plate; 2. Base; 3. Material sample; 4. Wedge block; 5. Spring; 6. Baffle; 7. Connecting hole; 8. Positioning block; 9. Positioning groove; 10. Slide groove; 11. Slider. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0016] Example This embodiment describes a tensile testing fixture for carbon fiber copper composite materials, such as... Figure 1 , Figure 2 and Figure 4 As shown, it includes two vertically arranged bases 2, which are symmetrically distributed at an interval between them; as Figure 1 and Figure 2 As shown, in this embodiment, the two bases 2 are distributed in a mirror-symmetrical manner to correspond to the upper and lower ends of the material sample 3. Both bases 2 can be detachably mounted with parallel and fitted pressure plates 1; such as Figure 1 , Figure 2 and Figure 4 As shown, in this embodiment, the pressure plate 1 is installed on the front side wall of the base 2 by two screws; the two screws are aligned and spaced apart from each other to facilitate placing the end of the material sample 3 between the two screws; at the same time, by tightening the two screws, the pressure plate 1 can apply a relatively uniform pressing force to the end of the material sample 3. Several positioning blocks 8 are fixed on the mounting surface of the pressure plate 1, and several positioning grooves 9 are provided on the mounting surface of the base 2 for independently engaging the positioning blocks 8, corresponding to all the positioning blocks 8; for example Figure 4 As shown, each pressure plate 1 has two positioning blocks 8 fixed on its mounting surface, which are spaced apart from each other on the left and right. The mounting surface of the base 2 has two positioning grooves 9 that are aligned with the positioning blocks 8. When the pressure plate 1 is detachably fixed to the base 2, the two positioning blocks 8 need to be inserted into the aligned positioning grooves 9. The positioning blocks 8 and the positioning grooves 9 are used to position the pressure plate 1, preventing the pressure plate 1 from shifting during use and further improving the stability when clamping the material sample 3. Each positioning block 8 has a chamfered corner at the end facing the positioning groove 9; for example Figure 4 As shown, when the positioning block 8 is inserted into the positioning groove 9, the chamfer can guide the positioning block 8 into the positioning groove 9, making the insertion process of the positioning block 8 easier and more convenient. The side of each base 2 that is in contact with the corresponding pressure plate 1 is the mounting surface; for example... Figure 2 As shown, the end of the material sample 3 is located between the mounting surfaces of the base 2 and the pressure plate 1 during the test; The mounting surfaces of the two bases 2 are provided with wedge-shaped grooves, and each wedge-shaped groove is provided with a wedge-shaped block 4 that slides within it; such as Figure 2As shown, the wedge block 4 has a trapezoidal structure, and the wedge groove is a trapezoidal groove structure that matches the wedge block 4. The bottom surface of the groove is inclined, and the distance between the bottom of the groove and the mounting surface of the base 2 gradually decreases along the pulling direction of the material sample 3. The bottom of the wedge groove matches the inclined surface of the wedge block 4. Figure 2 As shown, when the material sample 3 is pulled outward, the wedge block 4 will move towards the middle section of the material sample 3. Under the guidance of the inclined surface, the wedge block 4 will move outward and protrude from the wedge groove, thereby increasing the squeezing force of the wedge block 4 on the material sample 3 and further improving the clamping and fixing effect of the wedge block 4 and the pressure plate 1 on the material sample 3. like Figure 4 As shown, the left and right walls of the wedge-shaped groove are provided with mutually symmetrical sliding grooves 10. The two sliding grooves 10 are parallel to the inclined bottom of the wedge-shaped groove. The two side walls of the wedge-shaped block 4 are fixed with sliders 11 that can slide along the corresponding sliding grooves 10. When the wedge-shaped block 4 moves along the wedge-shaped groove, it will drive the sliders 11 to slide along the corresponding sliding grooves 10. Through the sliding cooperation of the sliding grooves 10 and the sliders 11, the wedge-shaped block 4 can be effectively prevented from coming out of the wedge-shaped groove. The two wedge-shaped blocks 4 are symmetrical from top to bottom; as Figure 2 As shown, during installation, the upper and lower ends of the material sample 3 are respectively attached to the two wedge blocks 4, and the two wedge blocks 4 and the corresponding pressure plates 1 clamp and fix the two ends of the material sample 3 respectively. Each wedge-shaped block 4 protrudes from the mounting surface facing the corresponding pressure plate 1, and is used to pre-tighten the material sample in conjunction with the corresponding pressure plate 1; for example Figure 2 As shown, in the initial state, the front sidewalls of the two wedge blocks 4 protrude slightly from the mounting surface of the base 2, so that the wedge blocks 4 and the corresponding pressure plates 1 can clamp and pre-tighten the ends of the material sample 3. In use, the two ends of the material sample 3 are respectively placed on the front sidewalls of the two wedge blocks 4, and then the two pressure plates 1 are fixed to the mounting surfaces of the base 2 of the two blocks with screws, so that the two wedge blocks 4 and the corresponding pressure plates 1 can clamp the two ends of the material sample 3 respectively, ensuring the initial pre-tightening force. During the tensile test, the material specimen 3 applies frictional force to the wedge block 4, causing the wedge block 4 to tend to slip within the wedge groove. At this point, thanks to the mechanical properties of the inclined plane, a portion of the force is converted into a compressive force exerted by the wedge block 4 on the material specimen 3. This conversion process significantly increases the contact pressure between the wedge block 4 and the material specimen 3, thereby enhancing the frictional force between them. As the tensile load continues to increase, the compressive force exerted by the wedge block 4 on the material specimen 3 also increases accordingly. This gradual increase in pressure effectively reduces the probability of slippage of the material specimen 3 during the tensile performance test, ensuring that the material specimen 3 is securely clamped throughout the entire tensile performance test. Ultimately, this mechanism guarantees the accuracy and stability of the mechanical property measurement of the material specimen 3.

[0017] To elaborate further, such as Figure 2 and Figure 4 As shown, this embodiment includes a spring 5, and a baffle 6 is detachably installed on the side wall of the base 2 facing the middle section of the material sample 3. In this embodiment, the baffle 6 is fixed to the side wall of the base 2 facing the middle section of the material sample 3 by screws, and the baffle 6 is fixed in a detachable manner to facilitate subsequent replacement or maintenance of the baffle 6. The spring 5 is installed between the baffle 6 and the wedge block 4. Figure 2 and Figure 4 As shown, the baffle 6 has a mounting groove on its side wall facing the wedge groove. One end of the spring 5 is inserted into the mounting groove to position the spring 5 and prevent it from shifting during use; the other end of the spring 5 is attached to the wedge block 4. During the tensile performance test, the wedge block 4 will compress the spring 5 as it moves. After the tensile performance test is completed and the material sample 3 is removed, the spring 5 will push the wedge block 4 back to its original position using its own properties, so that it can be used directly for the next test. This reduces the steps required for operators to move and adjust the position of the wedge block 4, reduces the workload of operators, and makes the operation simpler and more convenient. This solution constitutes a reset assembly for resetting the moved wedge block 4. Of course, the reset assembly can also use a spring plate. A baffle 6 is installed on the side wall of the base 2 facing the middle section of the material sample by screws. The spring plate is installed between the baffle 6 and the wedge block 4. During the tensile test, the wedge block 4 will squeeze the spring plate when it moves, causing the spring plate to compress. After the tensile test is completed and the material sample 3 is removed, the spring plate will push the wedge block 4 to move and reset through its own characteristics, so that it can be used directly for the next test.

[0018] Each pressure plate 1 has a slot on its mounting surface for limiting the position of the material sample; such as Figure 2 and Figure 4 As shown, when the wedge block 4 and the pressure plate 1 clamp and fix the material sample 3, the end of the material sample 3 will engage in the slot on the pressure plate 1. The slot can limit the position of the end of the material sample 3 to prevent lateral displacement during tensile performance testing. It also facilitates quick positioning of the end of the material sample 3 during installation. The bottom surface of the slot and the surface where the wedge block contacts the material sample are rough surfaces. Figure 4 As shown, in order to enhance the friction when clamping the material sample 3, the bottom surface of the slot and the contact surface where the wedge block and the material sample are in contact can be roughened. Specific methods include fine grinding, attaching high friction coefficient particles, or processing regular textures through specific processes to improve the roughness of these contact surfaces. Each base 2 is provided with a connection hole 7 for connecting to the working end of the universal testing machine; such as Figure 2 , Figure 3 and Figure 4 As shown, the connecting hole 7 is designed as a threaded hole and is located at the center of the end of the base 2. This layout ensures that the stress point of the entire fixture is located in the central area of ​​the width direction of the material sample 3 during the tensile performance test, thus effectively ensuring the uniformity of the stress on the material sample 3 during the test. The universal testing machine is a mature product and a precision instrument used to test the mechanical properties of materials. It can perform various tests such as tensile, compression, bending, shearing, peeling, and tearing, and is widely used in the mechanical property testing of metals, non-metals, and composite materials. Its working end consists of two tension rods arranged opposite each other. The ends of the two tension rods are respectively installed in the connecting holes 7 on the two bases 2, thereby fixing the tensile test fixture on the universal testing machine.

[0019] In practical use, the two ends of the material sample 3 are respectively placed against the front sidewalls of the two wedge blocks 4. Then, screws are used to fix the two pressure plates 1 to the mounting surfaces of the bases 2 of the two blocks, so that the two wedge blocks 4 and the corresponding pressure plates 1 can clamp the two ends of the material sample 3 respectively, ensuring the initial preload. During the tensile test, the material sample 3 applies frictional force to the wedge blocks 4, causing the wedge blocks 4 to slip within the wedge groove. At this time, thanks to the mechanical properties of the inclined plane, part of the force is converted into the compressive force applied by the wedge blocks 4 to the material sample 3. This conversion process significantly increases the contact pressure between the wedge blocks 4 and the material sample 3, thereby enhancing the friction between them. This increase in pressure effectively reduces the probability of slippage of the material sample 3 during the tensile performance test, making it less likely for the material sample 3 to slip between itself and the clamps, ensuring that the material sample 3 can be firmly clamped throughout the tensile performance test. During the tensile performance test, the wedge block 4 will compress the spring 5 as it moves. After the tensile performance test is completed and the material sample 3 is removed, the spring 5 will push the wedge block 4 to move and reset through its own recovery characteristics, so that it can be used directly in the next test. This reduces the steps for the staff to move and adjust the position of the wedge block 4, reduces the workload of the staff, and makes the operation process simpler and more convenient.

Claims

1. A tensile testing fixture for carbon fiber copper composite materials, comprising two vertically arranged bases (2), characterized in that: Two bases (2) are symmetrically distributed at intervals between the upper and lower parts. Each base (2) can be detachably installed with a pressure plate (1) that is parallel to it. The side of each base (2) that is in contact with the corresponding pressure plate (1) is the mounting surface. Wedge grooves are provided on the mounting surfaces of the two bases (2). Each wedge groove is provided with a wedge block (4) that is in sliding fit with it. The two wedge blocks (4) are symmetrical about the upper and lower parts. The side of each wedge block (4) facing the corresponding pressure plate (1) protrudes from the mounting surface and is used to cooperate with the corresponding pressure plate (1) to pre-tighten the material sample. Each base (2) is provided with a reset component for resetting the moved wedge block (4).

2. The tensile testing fixture for carbon fiber copper composite material according to claim 1, characterized in that: The reset assembly includes a spring (5), and a baffle (6) is detachably installed on the side wall of the base (2) facing the middle section of the material sample. The spring (5) is installed between the baffle (6) and the wedge block (4).

3. The tensile testing fixture for carbon fiber copper composite materials according to claim 1, characterized in that: Each pressure plate (1) has a groove on its mounting surface for limiting the material sample. The bottom surface of the groove and the surface where the wedge block contacts the material sample are rough surfaces.

4. The tensile testing fixture for carbon fiber copper composite material according to claim 1, characterized in that: Several positioning blocks (8) are fixed on the mounting surface of the pressure plate (1), and several positioning slots (9) for independently engaging the positioning blocks (8) are provided on the mounting surface of the base (2) for all positioning blocks (8).

5. The tensile testing fixture for carbon fiber copper composite material according to claim 4, characterized in that: Each positioning block (8) has a chamfer at the corner facing the positioning groove (9).

6. The tensile testing fixture for carbon fiber copper composite materials according to claim 1, characterized in that: Each base (2) is provided with a connection hole (7) for connecting the working end of the universal testing machine.

7. The tensile testing fixture for carbon fiber copper composite material according to claim 1, characterized in that: The two walls of the wedge-shaped groove are provided with mutually symmetrical sliding grooves (10). The two sliding grooves (10) are parallel to the bottom of the wedge-shaped groove. The two side walls of the wedge-shaped block (4) are fixed with sliders (11) that can slide along the corresponding sliding grooves (10).

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