Eight-point bending fatigue test tool based on tension-compression load effect

Abstract

The utility model provides an eight-point bending fatigue test tool based on tension-compression load action, which comprises an upper loading assembly, a lower loading assembly and a support assembly, a first support roller is arranged on the upper loading assembly, a second support roller is arranged on the lower loading assembly, and a third support roller is arranged on the support assembly; at least two sets of supporting assemblies are arranged, at least one set of supporting assemblies is the first supporting assembly, and the other sets of supporting assemblies are at least one set of second supporting assemblies. The first supporting assembly is connected with the upper loading assembly, the first supporting roller and the third supporting roller are oppositely arranged, and the first supporting roller and the third supporting roller clamp a to-be-tested piece; the second supporting assembly is connected with the lower loading assembly, the second supporting roller and the third supporting roller are oppositely arranged, and meanwhile the second supporting roller and the third supporting roller clamp a to-be-tested piece. The supporting roller is designed, so that even if the to-be-tested piece deforms in the test process, the supporting roller is cylindrical, and the loading point of the supporting roller and the test piece can be kept unchanged all the time.

Description

Technical Field

[0001] The utility model relates to a test tool, in particular to an eight-point bending fatigue test tool based on tension-compression load action. Background Art

[0002] Adding coatings to metal surfaces is an effective means of improving the performance of metal materials, particularly their corrosion and wear resistance. Currently, widely used protective processes include electroplating and spraying. These coatings or platings isolate the substrate from the external environment, significantly improving the corrosion, hydrogen embrittlement, and wear resistance of ultra-high-strength steel surfaces and extending the service life of components made of these materials.

[0003] One existing technique involves an out-of-plane compression-micro-tension fatigue test using a test bench equipped with four compression springs. However, this test method and fixture primarily focuses on compression fatigue and cannot achieve full tension-compression fatigue testing. Another method, which measures the out-of-plane fatigue strength of L-shaped carbon fiber reinforced composite unidirectional sheet materials through a four-point bending fatigue test, is the use of a fixture capable of applying only compression-compression fatigue loads, not tension-compression fatigue loads. Summary of the Invention

[0004] The purpose of the utility model is to solve the above problems and provide an eight-point bending fatigue test tool based on tension-compression load action.

[0005] In order to achieve the above-mentioned purpose of the utility model, the utility model provides an eight-point bending fatigue test fixture based on tension-compression load, including an upper loading assembly, a lower loading assembly and a support assembly, a first support roller is arranged on the upper loading assembly, a second support roller is arranged on the lower loading assembly, and a third support roller is arranged on the support assembly; the support assembly is provided with at least two groups, at least one group is a first support assembly, the rest are second support assemblies and there is at least one group of second support assemblies; the first support assembly is connected to the upper loading assembly, the first support roller and the third support roller are arranged opposite to each other, and the first support roller and the third support roller clamp the test piece; the second support assembly is connected to the lower loading assembly, the second support roller and the third support roller are arranged opposite to each other, and the second support roller and the third support roller clamp the test piece.

[0006] More specifically, a baffle group for limiting the movement of the test piece in the length direction is provided on the upper loading assembly, and the baffle group includes a first baffle and a second baffle, and the first baffle and the second baffle are respectively provided at both ends of the upper loading assembly.

[0007] More specifically, first connecting blocks are set at both ends of the first supporting assembly, and the first supporting assembly is connected to the upper loading assembly through the first connecting blocks; second connecting blocks are set at both ends of the second supporting assembly, and the second supporting assembly is connected to the lower loading assembly through the second connecting blocks.

[0008] More specifically, a limiting member for limiting the movement of the test piece in the width direction is provided on the first connecting block, and the second connecting block has the same structure as the first connecting block.

[0009] More specifically, the upper loading assembly includes an upper connecting head, an upper loading head connected to the upper connecting head, and an upper support seat connected to the upper loading head, the upper support seat is connected to the first connecting block, and an upper placing piece is provided on the side of the upper support seat close to the first connecting block, and the first support roller is provided on the upper placing piece.

[0010] More specifically, the upper support seat is movably connected to the upper loading head.

[0011] More specifically, a slide groove is provided on a side of the upper loading head close to the upper support seat, a movable slider is provided in the slide groove, and the upper support seat is connected to the slider.

[0012] More specifically, the lower loading assembly includes a lower connecting head, a lower loading head connected to the lower connecting head, and a lower support seat connected to the lower loading head. The lower support seat is connected to the second connecting block. A lower placing piece is provided on the side of the lower support seat close to the second connecting block, and the second support roller is provided on the lower placing piece.

[0013] More specifically, a slide groove is provided on a side of the lower loading head close to the lower support seat, a movable slider is provided in the slide groove, and the lower support seat is connected to the slider.

[0014] More specifically, the support assembly includes a support plate and a support placement piece arranged on the support plate, the support plate is connected to the connecting block, the support placement piece is arranged on a side close to the connecting block, and the third support roller is arranged on the support placement piece.

[0015] More specifically, the upper placement piece is provided with a V-shaped groove, and the first supporting roller is placed in the groove of the upper placement piece; the lower placement piece, the supporting placement piece and the upper placement piece have the same structure.

[0016] This utility model primarily designs an eight-point bending fatigue test fixture based on tensile and compressive loads. The fixture features a rationally designed structure, effectively testing the coating material's ability to withstand tensile and compressive loads. Furthermore, the design of the support roller ensures that even if the test piece deforms during the test, the cylindrical support roller and the test piece maintain a constant loading point. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described below are only used to explain the present application and are not intended to limit the scope of the present application. In the accompanying drawings:

[0018] Figure 1 It is a three-dimensional structural diagram of the utility model;

[0019] Figure 2 This is a schematic diagram of the three-dimensional structure of the upper connector of the utility model;

[0020] Figure 3 This is a schematic diagram of the three-dimensional structure of the upper loading head of the utility model;

[0021] Figure 4 This is a schematic diagram of the three-dimensional structure of the upper support seat and the test piece of the utility model;

[0022] Figure 5 This is a schematic diagram of the three-dimensional structure of the support assembly of the utility model;

[0023] Figure 6 This is a schematic diagram of the three-dimensional structure of the connection block and the limiting member of the utility model;

[0024] Figure 7 It is a side structural schematic diagram of the utility model;

[0025] Figure 8 This utility model Figure 7 AA section view;

[0026] Figure 9 This is a schematic diagram of the main structure of the utility model;

[0027] Figure 10 This utility model Figure 9 CC cross-sectional view;

[0028] In the figure: 11, upper connecting head; 12, upper loading head; 121, first slide groove; 122, first countersunk bolt hole; 123, slider; 13, upper support seat; 14, upper placement piece; 15, first support roller; 16, first baffle; 17, second baffle; 21, lower connecting head; 22, lower loading head; 23, lower supporting seat; 24, lower placement piece; 25, second support roller; 31, support plate; 32, support placement piece; 33, third support roller; 41, connecting block; 42, limit piece; 5, piece to be tested. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the implementation of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below in conjunction with the drawings in the embodiments of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be understood as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention. The following is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings.

[0031] It should be understood that the drawings are only used to illustrate the present application.

[0032] An eight-point bending fatigue test fixture based on tension-compression load, such as Figures 1-10 As shown, it includes an upper loading component, a lower loading component, a supporting component and a connecting block 41.

[0033] The upper loading assembly includes an upper connecting head 11, an upper loading head 12 connected to the upper connecting head 11, and an upper supporting seat 13 connected to the upper loading head 12. The upper chuck of the fatigue testing machine clamps the upper loading assembly.

[0034] like Figures 1-10As shown, the upper connecting head 11 is composed of two cylindrical sections, the upper cylindrical section has a larger diameter and is used to be clamped by the upper chuck of the fatigue testing machine. The lower cylindrical section has an external thread for easy connection with the upper loading head 12.

[0035] like Figure 1-Figure 2 、 Figure 7-10 As shown, the upper loading head 12 is an arched block with a thickened middle area. A first countersunk bolt hole 122 is provided in the middle area of ​​the upper loading head 12. The first countersunk bolt hole 122 is used to connect with the lower cylindrical section of the upper connecting head 11. The lower cylindrical section is directly screwed into the first countersunk bolt hole 122 to ensure the reliability of the connection. The upper support seat 13 is movably connected to the upper loading head 12. A first slide groove 121 is provided on the side of the upper loading head 12 close to the upper support seat 13. A movable slider 123 is provided in the first slide groove 121. The upper support seat 13 is connected to the slider 123. To ensure the reliable connection between the upper support seat 13 and the upper loading head 12, two first slide grooves 121 arranged parallel to the length direction are provided on the lower side of the upper loading head 12. A slider 123 is provided in each first slide groove 121 to facilitate the horizontal sliding of the upper support seat 13 in the first slide groove 121 to adjust its position.

[0036] like Figure 1 、 Figure 4 、 Figure 7-10As shown, the upper and lower ends of the upper support seat 13 protrude to both sides. The end close to the upper loading head 12 protrudes along the length direction of the upper loading head 12, and the end away from the upper loading head 12 protrudes along the width direction of the upper loading head 12. The first protruding block protrudes along the length direction of the upper loading head 12, and the second protruding block protrudes along the width direction of the upper loading head 12. A first sliding connection bolt hole is provided on the first protruding block. The first sliding connection bolt hole corresponds to the position of the first slide groove 121 of the upper loading head 12. The first sliding connection bolt hole is used to be screwed to the upper loading head 12 via a sliding connection bolt. The sliding connection bolt passes through the first sliding connection bolt hole and connects to the slider 123 in the first slide groove 121. Pushing the upper support seat 13 causes the slider 123 to move in the first slide groove 121, thereby adjusting the horizontal position of the upper support seat 13. A first connection bolt hole is provided on the second protruding block. The first connection bolt hole is provided with a first connection bolt. An upper placement member 14 is provided on the side of the upper support base 13 near the support assembly. The first support roller 15 is disposed on the upper placement member 14. Specifically, a V-shaped groove is provided on the upper placement member 14, and the first support roller 15 is positioned within the V-shaped groove of the upper placement member 14. The first support roller 15 protrudes from the upper placement member 14 to prevent the upper placement member 14 from blocking the first support roller 15 from clamping the test piece 5 during testing. The upper placement member 14 can be configured in an M-shape or in two trapezoidal shapes connected side by side, as long as a stable connection with the upper support base is ensured.

[0037] like Figure 4 As shown, the first support roller 15 is configured as a cylindrical structure. When the first support roller 15 is placed on the upper placement member 14, the first support roller 15 protrudes from the upper placement member 14. When clamping the test piece 5, the first support roller 15 contacts the test piece 5, while the upper placement member 14 does not contact the test piece 5. Of course, the first support roller 15 can also be configured as a rectangular structure, but the cylindrical structure ensures that no matter how the test piece 5 deforms, the cylindrical first support roller 15 can maintain the loading point on the test piece 5 unchanged.

[0038] The upper support seat 13 may be provided with only one, but in order to ensure the reliability of the test of the test piece 5, the upper support seat 13 is provided with two.

[0039] like Figure 1 、 Figure 5 、 Figure 7-10As shown, a support assembly is connected to the upper support seat 13. The support assembly is arranged according to the number of upper support seats 13 and lower support seats 23. Since there is at least one upper support seat 13 and at least one lower support seat 23, the support assembly is provided in at least two groups, at least one of which is a first support assembly and the rest are second support assemblies. The second support assembly is provided in at least one group. The first support assembly is connected to the upper support seat 13 and the second support assembly is connected to the lower support seat 23. In this embodiment, there are two upper support seats 13, so there are also two first support assemblies. The second support assembly has the same structure as the first support assembly. The support assembly includes a support plate 31 and a support placement member 32 arranged on the support plate 31. The support placement member 32 has a third support roller 33 arranged therein. The support placement member 32 has the same structure as the upper placement member 14. Third connecting bolt holes are provided at both ends of the support plate 31 for connecting to the upper support seat 13 or the lower support seat 23. The supporting placement member 32 is arranged on a side close to the upper supporting seat 13 or the lower supporting seat 23, and the third supporting roller 33 is arranged on the supporting placement member 32. When the upper supporting seat 13 is connected to the first supporting assembly, the first supporting roller 15 and the third supporting roller 33 are arranged opposite to each other, and the first supporting roller 15 and the third supporting roller 33 clamp the test piece 5.

[0040] like Figure 1 、 Figures 6-10 As shown, when the support plate 31 is connected to the upper support seat 13, the first connecting bolt can be directly passed through the first connecting bolt hole and the third connecting bolt hole to connect them. The first connecting bolt can be adjusted according to the thickness of the test piece 5. However, if the thickness of the test piece 5 is thicker, the length of the first connecting bolt may not be enough, so a connecting block 41 is provided for connection. The connecting block 41 includes a first connecting block and a second connecting block. The first connecting block is provided at both ends of the first supporting assembly. Specifically, the first connecting block is provided at both ends of the support plate 31. The first supporting assembly is connected to the upper loading assembly through the first connecting block. The second connecting bolt hole is provided at both ends of the first connecting block. When the upper support seat 13 is connected to the first connecting block, the first connecting bolt passes through the first connecting bolt hole and the second connecting bolt hole to connect them. Similarly, when the support plate 31 is connected to the first connecting block, the second connecting bolt passes through the third connecting bolt hole and the third connecting bolt hole to connect them. The distance between the upper support seat 13 and the support plate 31 is adjusted by adjusting the first and second connecting bolts to leave a suitable height for the test piece 5.

[0041] like Figure 1 、 Figures 6-10As shown, during the test of the test piece 5, the test piece 5 may move, which may affect the test results. Therefore, a limiting hole is provided in the first connecting block. A limiting member 42 is provided in the limiting hole to limit the movement of the test piece 5 in the width direction. The limiting member 42 can be configured as any structure capable of preventing the movement of the test piece 5. In this embodiment, the limiting member 42 is configured as a bolt. A baffle group is provided on the upper loading assembly to limit the movement of the test piece 5 in the length direction. The baffle group includes a first baffle 16 and a second baffle 17. The first baffle 16 and the second baffle 17 are respectively provided at both ends of the upper loading assembly.

[0042] like Figure 1 、 Figure 7-10 As shown, the lower loading assembly includes a lower connecting head 21, a lower loading head 22 connected to the lower connecting head 21, and a lower support seat 23 connected to the lower loading head 22. The structure of the lower loading assembly is the same as that of the upper loading assembly, except that the lower loading head 22 is configured as a rectangular block without a thickened area in the middle. A second chute is provided on the side of the lower loading head 22 near the lower support seat 23, and a movable slider 123 is provided in the second chute. The lower support seat 23 is connected to the slider 123. Two lower support seats 23 are provided, and the horizontal distance between the two lower support seats 23 is the second span. The horizontal distance between the two upper support seats 13 is the first span. The second span is greater than the first span, and the two upper support seats 13 are located between the two lower support seats 23.

[0043] The lower support base 23 is connected to the second support assembly. To better accommodate different test samples, second connecting blocks are provided at both ends of the second support assembly. The second support assembly is connected to the lower loading assembly via the second connecting blocks. The second connecting blocks have the same structure as the first connecting blocks. A lower placement member 24 is provided on the side of the lower support base 23 near the second connecting block. The second support roller 25 is provided on the lower placement member 24. The lower placement member 24 has the same structure as the upper placement member 14. When the second support assembly is connected to the lower loading assembly, the second support roller 25 and the third support roller 33 are arranged opposite each other, and the second support roller 25 and the third support roller 33 clamp the test sample 5.

[0044] The specific connection method between the lower loading assembly and the second supporting assembly is the same as the connection method between the upper loading assembly and the first supporting assembly, and will not be repeated here.

[0045] In summary, support rollers are set on the placement piece to ensure that no matter how the test piece 5 is deformed during the test, the support rollers can ensure that the loading point of the test piece 5 remains unchanged; a baffle group and a limit member 42 are set to ensure that the position of the test piece 5 does not change during the test, thereby ensuring the reliability of the test. The baffle group and the limit member 42 can be adjusted according to the size of the test piece 5; a connecting block 41 is set to facilitate adjustment according to the thickness of the test piece 5 to accommodate more sizes of test pieces 5; the upper support seat 13 can move along the upper loading head 12, and the lower support seat 23 can move along the lower loading head 22, so as to facilitate adjustment of the positions of the upper loading head 12 and the lower loading head 22 to accommodate different test pieces 5.

[0046] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0048] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An eight-point bending fatigue test tool based on tension-compression load, characterized in that: It comprises an upper loading component, a lower loading component and a supporting component, wherein a first supporting roller (15) is arranged on the upper loading component, a second supporting roller (25) is arranged on the lower loading component, and a third supporting roller (33) is arranged on the supporting component; The support assemblies are provided in at least two groups, at least one of which is a first support assembly, and the rest are second support assemblies and at least one of which is a second support assembly; The first support assembly is connected to the upper loading assembly, the first support roller (15) and the third support roller (33) are arranged opposite to each other, and the first support roller (15) and the third support roller (33) clamp the test piece (5); the second support assembly is connected to the lower loading assembly, the second support roller (25) and the third support roller (33) are arranged opposite to each other, and the second support roller (25) and the third support roller (33) clamp the test piece (5).

2. The eight-point bending fatigue test tool based on tension-compression load according to claim 1 is characterized in that: A baffle plate group is provided on the upper loading assembly to limit the movement of the test piece (5) in the length direction, and the baffle plate group comprises a first baffle plate (16) and a second baffle plate (17). The first baffle plate (16) and the second baffle plate (17) are respectively provided at two ends of the upper loading assembly.

3. The eight-point bending fatigue test tool based on tension-compression load according to claim 1 is characterized in that: A first connection block is provided at both ends of the first support assembly, and the first support assembly is connected to the upper loading assembly through the first connection block; a second connection block is provided at both ends of the second support assembly, and the second support assembly is connected to the lower loading assembly through the second connection block.

4. The eight-point bending fatigue test tool based on tension-compression load according to claim 3 is characterized in that: A limiting member (42) for limiting the movement of the test piece (5) in the width direction is arranged on the first connecting block, and the second connecting block has the same structure as the first connecting block.

5. The eight-point bending fatigue test tool based on tension-compression load according to claim 4 is characterized in that: The upper loading assembly comprises an upper connecting head (11), an upper loading head (12) connected to the upper connecting head (11), and an upper supporting seat (13) connected to the upper loading head (12); the upper supporting seat (13) is connected to a first connecting block; an upper placing piece (14) is arranged on a side of the upper supporting seat (13) close to the first connecting block; and the first supporting roller (15) is arranged on the upper placing piece (14).

6. The eight-point bending fatigue test tool based on tension-compression load according to claim 5 is characterized in that: The upper support seat (13) can move along the upper loading head (12).

7. The eight-point bending fatigue test tool based on tension-compression load according to claim 5 is characterized in that: A slide groove is provided on one side of the upper loading head (12) close to the upper support seat (13), a movable slider (123) is arranged in the slide groove, and the upper support seat (13) is connected to the slider (123).

8. The eight-point bending fatigue test tool based on tension-compression load according to claim 5 is characterized in that: The lower loading assembly comprises a lower connecting head (21), a lower loading head (22) connected to the lower connecting head (21), and a lower supporting seat (23) connected to the lower loading head (22); the lower supporting seat (23) is connected to a second connecting block; a lower placing piece (24) is arranged on a side of the lower supporting seat (23) close to the second connecting block; and the second supporting roller (25) is arranged on the lower placing piece (24).

9. The eight-point bending fatigue test tool based on tension-compression load according to claim 8, characterized in that: The support assembly comprises a support plate (31) and a support placement member (32) arranged on the support plate (31); the support plate (31) is connected to a connecting block (41); the support placement member (32) is arranged on a side close to the connecting block (41); and the third support roller (33) is arranged on the support placement member (32).

10. The eight-point bending fatigue test tool based on tension-compression load according to claim 9, characterized in that: A V-shaped groove is provided on the upper placement piece (14), and the first support roller (15) is placed on the V-shaped groove; the lower placement piece (24), the support placement piece (32) and the upper placement piece (14) have the same structure.

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