A buckling-restrained device and method for cyclic tension-compression loading of a differential-thickness plate specimen

Abstract

The application relates to a buckling-restrained device and method for cyclic tensile-compressive loading of a differential-thickness plate sample, and belongs to the technical field of metal plate testing. The device comprises a clamp assembly for clamping two ends of the sample, and a buckling-restrained assembly for restraining the transition zone of the sample during loading. The buckling-restrained assembly comprises at least two sliders symmetrically arranged on both sides of the transition zone of the sample, and the contact surfaces of the sliders are matched with the surface of the transition zone of the sample. An elastic force assembly is connected with the sliders, and during the cyclic tensile-compressive loading, the elastic force assembly applies a continuous elastic force to the sliders in the direction of the sample, so that the contact surfaces of the sliders are always closely attached to the surface of the transition zone of the sample. The application continuously applies a constraint to the thickness direction of the transition zone of the aluminum alloy differential-thickness plate sample through dynamic adjustment of the sliders during the cyclic tensile-compressive loading, avoids the appearance of a gap in the thickness direction due to the thickness change of the transition zone, and effectively suppresses the buckling deformation of the sample during the cyclic tensile-compressive loading.

Description

Technical Field

[0001] This invention belongs to the field of metal sheet testing technology, and particularly relates to an anti-buckling device and method for cyclic tensile and compressive loading of differential thickness plate samples. Background Technology

[0002] The main characteristic of sheet metal produced using variable thickness rolling technology is that its thickness varies periodically along the longitudinal or transverse direction. After cutting, sheet metal with specific thin and thick sections can be obtained, with a transition zone between the thin and thick sections providing a continuous thickness transition. Compared to laser-welded sheets, this technology achieves better formability and higher surface quality while saving material and reducing weight. Currently, lightweighting is a major goal in automotive design and manufacturing, and variable thickness sheets are already used to manufacture numerous components such as B-pillars, crash beams, and front longitudinal beams to achieve lightweighting objectives.

[0003] Furthermore, aluminum alloys, due to their lightweight and high strength, can significantly reduce vehicle weight and energy consumption. Combining variable thickness rolling technology with aluminum alloys can simultaneously improve the mechanical properties of aluminum alloy plates with varying thicknesses, further advancing the development of lightweight vehicles. The primary strengthening mechanism of aluminum alloys is precipitation strengthening, and the commonly used heat treatment process combines solution treatment and aging treatment. Current research reports that room temperature cyclic tensile and compressive loading of aluminum alloy plates of uniform thickness can achieve peak aged strength while maintaining good elongation. This strengthening method can effectively reduce heat treatment time, lower costs, and improve production efficiency.

[0004] To investigate the differences in mechanical properties and strengthening effects between the constant thickness zone and the transition zone of aluminum alloy differential thickness plates after cyclic tensile and compressive loading, it is necessary to cut specimens of fixed dimensions for testing. During cyclic tensile and compressive loading, the deformation zone of the specimen often exhibits buckling deformation in the thickness direction due to the high deformation resistance in the loading direction under compressive stress. This buckling severely affects the loading effect, thus requiring additional buckling-resistance devices to suppress buckling deformation in the thickness direction. Most current buckling-resistance devices are designed for constant thickness plates, where the thickness variation is more uniform and the working surface of the fixture is often planar. During loading, the fixture can limit buckling deformation in the thickness direction by continuously clamping the specimen. However, for differential thickness plates, the thickness gradient characteristics of the transition zone make it impossible for a planar fixture to adapt to the thickness gradient variation of the specimen, resulting in a gap of varying width along the loading direction, i.e., a wedge-shaped gap. Therefore, buckling in the thickness direction is difficult to limit during loading, leading to a change in the net shape of the specimen.

[0005] Therefore, in order to better utilize aluminum alloy differential thickness plate specimens for testing and ensure loading effect, it is necessary to design an anti-buckling device and method to assist in cyclic tensile and compressive loading of aluminum alloy differential thickness plates in the transition zone, so as to gain a deeper understanding of the overall performance changes and underlying mechanisms of aluminum alloy differential thickness plates under cyclic tensile and compressive loading. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an anti-buckling device and method for cyclic tensile and compressive loading of aluminum alloy differential thickness plate specimens. By dynamically adjusting the slider during the cyclic tensile and compressive loading process, the thickness direction of the transition zone of the aluminum alloy differential thickness plate specimen is continuously constrained, preventing gaps along the thickness direction caused by changes in the thickness of the transition zone. This effectively suppresses buckling deformation of the specimen during the cyclic tensile and compressive loading process, providing a reliable experimental device and method for in-depth research on the mechanical properties and strengthening mechanism of aluminum alloy differential thickness plates under cyclic tensile and compressive loading.

[0007] A buckling-resistance device for cyclic tensile and compressive loading of differential thickness plate specimens includes:

[0008] The clamping assembly grips both ends of the sample;

[0009] An anti-buckling component is disposed between the two gripping ends of the clamping assembly to constrain the transition zone of the specimen during loading.

[0010] The buckling protection component includes:

[0011] At least two sliders are symmetrically arranged on both sides of the transition zone of the sample, and each slider has a contact surface that is adapted to the surface of the transition zone of the sample.

[0012] The elastic force application component, connected to the slider, is used to apply a continuous elastic force pointing towards the specimen during cyclic tensile and compressive loading, so that the contact surface of the slider is always in close contact with the surface of the specimen transition zone, thereby adaptively eliminating the gap caused by changes in specimen thickness.

[0013] The clamping assembly includes an upper clamp and a lower clamp, the upper clamp being used to clamp the first end of the sample and the lower clamp being used to clamp the second end of the sample.

[0014] The upper clamp and / or lower clamp include a pair of oppositely arranged plate-shaped structural members connected by fasteners to clamp the ends of the sample.

[0015] The plate-shaped structural member is connected to the anti-buckling component at one end, which has a through groove along the thickness direction to form a comb-like structure. The end of the slider is provided with a comb-like structure that meshes with it. In the unloaded state, the meshing length is half the length of the comb teeth.

[0016] The elastic force application component includes:

[0017] A slider fixing plate is disposed on the outside of the slider to accommodate and guide the slider to slide in a predetermined direction;

[0018] At least one push rod: slidably mounted on the slider fixing plate, with the end of the push rod abutting against the slider;

[0019] An elastic element is located between the front end of the push rod and the connecting bolt to provide elastic force.

[0020] The slider and the slider fixing plate are connected by a mutually cooperating guide structure to guide the sliding direction of the slider.

[0021] The guide structure includes auxiliary sliders that are inclined downwards on both sides of the slider and a groove on the inner wall of the slider fixing plate. The auxiliary sliders are slidably embedded in the grooves, and the embedded length does not exceed 10mm.

[0022] Both the auxiliary slider and the groove have an angle with the horizontal direction, and the angle of the angle is consistent with the slope of the sample transition zone.

[0023] The contact surface of the slider is an inclined plane, and the slope of the inclined plane is consistent with the slope of the sample transition zone.

[0024] A buckling-resistance method using the aforementioned buckling-resistance device for cyclic tensile-compressive loading of a differential thickness plate specimen specifically includes the following steps:

[0025] S1: Place the transition zone of the sample between at least two symmetrically arranged sliders, and make the contact surface of the sliders fit against the surface of the transition zone of the sample.

[0026] S2: Apply a continuous elastic force, directed toward the sample direction, to the slider through the elastic force application component;

[0027] S3: Clamp and fix both ends of the sample with the clamp assembly respectively;

[0028] S4: Cyclic tensile and compressive loading is applied to the sample. During the loading process, the slider slides adaptively under the action of elastic force, so that the contact surface of the slider is always in close contact with the surface of the sample thickness change, thereby suppressing buckling deformation.

[0029] By employing the above technical solution, the present invention has at least the following beneficial effects:

[0030] (1) This invention provides a simple, easy-to-process, and widely applicable device and method for anti-buckling under cyclic tension and compression loading of differential thickness plates. The device consists of an upper clamp, an anti-buckling clamp, and a lower clamp, which is easy to assemble and use. Each part can be obtained by simple processing such as wire cutting and drilling of the steel plate. For a slider, as long as the slope of the loading area is consistent with the slope of the slider and the slope of the small slider, the transition zone loading of aluminum alloy differential thickness plates with various thickness ratios and shapes can be performed without the need for additional device design.

[0031] (2) The device provided by this invention can be used for cyclic tensile and compressive loading, which can realize cyclic tensile and compressive loading in the transition zone of aluminum alloy differential thickness plates. During the loading process, the sample will be continuously clamped by the adaptive sliding of the slider. After loading is completed, the sample will not change its net shape. Attached Figure Description

[0032] Figure 1 A schematic diagram of the anti-buckling device for cyclic tensile and compressive loading of differential thickness plate specimens provided by the present invention;

[0033] Figure 2 This is a front view of an anti-buckling device for cyclic tensile and compressive loading of differential thickness plate specimens provided by the present invention;

[0034] Figure 3 A schematic diagram of the upper clamp in an anti-buckling device for cyclic tensile and compressive loading of differential thickness plate specimens provided by the present invention;

[0035] Figure 4 A schematic diagram of the lower clamp in an anti-buckling device for cyclic tensile and compressive loading of differential thickness plate specimens provided by the present invention;

[0036] Figure 5 This is a front view of the slider structure of the present invention;

[0037] Figure 6 This is a side view of the slider structure of the present invention;

[0038] Figure 7 This is a front view of the slider fixing plate of the present invention;

[0039] Figure 8 for Figure 7 AA view;

[0040] Figure 9 This is a front view of the push rod structure of the present invention;

[0041] Figure 10 for Figure 9 Side view;

[0042] Figure 11 This is a three-dimensional schematic diagram of a plate with varying thickness (where B is the thick region, C is the transition region, and D is the thin region).

[0043] Figure 12 This is a front view of the aluminum alloy differential thickness plate sample used in an embodiment of the present invention;

[0044] Figure 13 for Figure 12 Side view;

[0045] Figure 14 The graph shows the results obtained from finite element simulation experiments using this invention.

[0046] In the picture:

[0047] 1. Upper clamp; 2. Clamp fastening nut; 3. Clamp fastening bolt; 4. Slider; 5. Slider fixing plate; 6. Push rod; 7. Spring; 8. Bolt; 9. Lower clamp; 10. Fixing plate fastening bolt; 11. Fixing plate fastening nut; 12. Sample; 13. Auxiliary slider; 14. Slide groove. Detailed Implementation

[0048] To better explain and facilitate understanding of the present invention, the technical solution and effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figures 1-10 As shown, a buckling-resistant device for cyclic tensile and compressive loading of a differential thickness plate specimen includes an upper clamp 1, a buckling-resistant component, and a lower clamp 9. The aluminum alloy differential thickness plate specimen 12 is placed in the middle of the buckling-resistant clamp, and the entire device is symmetrically arranged along the length of the specimen 12.

[0050] The upper clamp 1 and the lower clamp 9 are both paired plate-shaped structural components with a comb-shaped structure.

[0051] Specifically, the upper clamp 1 includes two plate-shaped structural members, arranged side-by-side opposite the sample 12 and connected by clamp fastening bolts 3 and fastened by clamp fastening nuts 2, used to clamp the upper clamping section of the sample 12. The upper clamp 1 has multiple through slots along the thickness direction at its connection end with the buckling-resistance component, forming a comb-like structure. The comb-like structure is located at the center of the plate-shaped structural members, and its dimensions should match the comb-like structure of the slider 4 in the buckling-resistance component. The length of the concave teeth meets the requirements of the loaded strain magnitude.

[0052] The lower clamp 9 also includes two plate-shaped structural members, arranged side-by-side opposite the sample 12 and connected by clamping bolts 3 and clamping nuts 2. It is symmetrical to the upper clamp 1 and is used to clamp the lower holding section of the sample 12. The lower clamp 9 has multiple through slots along its thickness at its connection end with the buckling-resistance component, forming a comb-like structure. The comb-like structure is located at the center of the plate-shaped structural member, and its dimensions should match the comb-like structure of the slider 4 in the buckling-resistance component. The length of the concave teeth meets the requirements of the loaded strain magnitude.

[0053] The comb-shaped connecting end of the upper clamp 1 is located at the bottom, and the comb-shaped connecting end of the lower clamp 9 is located at the top. Before loading, the engagement length between the comb-shaped structure of the upper clamp 1 and the lower clamp 9 and the two ends of the buckling-resistance component is half of the comb teeth. The lower clamp of the tensile testing machine clamps the remaining length of the specimen 12 in the clamping section where the lower clamp 9 is located, and the upper clamp of the tensile testing machine clamps the remaining length of the specimen 12 clamping section reserved at the upper end of the upper clamp 1. The tensile testing machine drives the upper clamp 1 and the lower clamp 9 to reciprocate up and down relative to the slider 4 to apply cyclic tensile and compressive loads. During the loading process, the upper clamp 1 and the lower clamp 9 move up and down with the clamp of the tensile testing machine but do not slide relative to each other.

[0054] The buckling-resistant assembly includes sliders 4, slider fixing plates 5, push rods 6, springs 7, and bolts 8. The two sliders 4 are symmetrically arranged relative to the specimen 12, i.e., they are in contact with the inclined surface of the specimen 12. The two slider fixing plates 5 are symmetrically arranged outside the two sliders 4 and connected by fixing plate fastening bolts 10 and fastened by fixing plate fastening nuts 11. The two push rods 6 pass through the two slider fixing plates 5 from the outside, with their ends abutting against the two sliders 4 respectively. The push rods 6 are connected to the slider fixing plates 5 via springs 7 and bolts 8. The ends of the bolts 8 are connected to the slider fixing plates 5, and the springs 7 are sleeved on the outside of the bolts. The push rods 6 can slide within the slider fixing plates 5, and simultaneously, through the action of the springs 7, are always in contact with the sliders 4.

[0055] Specifically, two sliders 4 are symmetrically arranged on both sides of the sample 12, contacting the two inclined surfaces of the sample 12 respectively. The sliders 4 are in complete contact with the sample 12, and the contact surfaces are inclined. The slope of the contact surfaces is the same as the slope of the transition area of ​​the sample 12, and the width of the contact surfaces is the same as the width of the parallel section of the sample 12. The thickness of the sliders 4 can be determined according to the usage requirements and is specifically determined according to the strength of the processing material used, so that the sliders 4 should not deform during loading. As a preferred embodiment, a polytetrafluoroethylene film is further provided on the contact surface between the sliders 4 and the sample 12 to reduce the friction between the sample 12 and the sliders 4, which is more conducive to the loading effect. Furthermore, the upper and lower ends of the sliders 4 have grooves that penetrate along the thickness direction, forming a comb-like structure, which mesh with the upper clamp 1 and the lower clamp 9 respectively. Except for the comb-like area, the length of the sliders 4 is the same as the length of the parallel section of the sample 12. Furthermore, auxiliary sliders 13 are symmetrically arranged on both sides of the slider 4, inserted into the grooves 14 of the slider fixing plate 5. The back-and-forth sliding of the auxiliary sliders 13 within the grooves 14 causes the slider 4 to move up and down. That is, during the loading process, when the thickness of the parallel section of the sample 12 changes, the distance and direction of the slider 4's up-and-down movement are adjusted by the back-and-forth sliding of the auxiliary sliders 13. The auxiliary sliders 13 are inclined downwards, forming an angle with the horizontal direction. The angle between the auxiliary sliders 13 and the horizontal plane is consistent with the slope of the transition zone of the sample 12. Furthermore, the dimensions of the auxiliary sliders 13 need to be designed based on consideration of strength, but their length inserted into the grooves 14 of the slider fixing plate 5 shall not exceed 10 mm.

[0056] The slider fixing plate 5 is disposed outside the slider 4, located between the upper clamp 1 and the lower clamp 9, and the two slider fixing plates 5 enclose the two sliders 4 from the outside. The groove 14 is formed on the inner wall of the slider fixing plate 5 for cooperation with the auxiliary slider 13. The slider fixing plate 5 is used in conjunction with the slider 4. Specifically, a rectangular groove penetrating the top and bottom is formed on one side of the slider fixing plate 5, making the slider fixing plate 5 have an overall concave structure. The size of the rectangular groove is the same as the size of the slider 4. When the slider 4 is placed in the slider fixing plate 5, it should be ensured that only the inclined surface of the slider 4 protrudes from the slider fixing plate 5. The groove 14 is formed on two opposite inner walls of the rectangular groove. The size of the groove 14 is the same as the size of the auxiliary slider 13 of the slider 4. At the same time, the groove 14 also has an angle with the horizontal direction, and the angle of this angle is the same as the slope of the transition zone of the sample 12.

[0057] To achieve the connection of the push rod 6, a φ8 through hole is provided at the center of the surface corresponding to the opening side of the rectangular groove on the slider fixing plate 5. The push rod 6 passes through the through hole and abuts against the outer surface of the slider 4. The push rod 6 can generate horizontal relative movement along the through hole. During loading, under the action of the spring 7, the push rod 6 continuously presses against the slider 4. When the thickness changes in the transition zone of the sample 12, the slider 4 achieves adaptive sliding through the interaction between the push rod 6 and the slider 4. Since the slider fixing plates 5 are fastened together by the fixing plate fastening bolts 10 and the fixing plate fastening nuts 11, the position of the slider fixing plates 5 relative to the ground remains unchanged during loading.

[0058] Furthermore, the push rod 6 consists of a cylindrical advancing section with a diameter of φ8 and a tail baffle. A spring 7 is positioned between the tail baffle and the nut of the bolt 8. Under the condition of meeting strength requirements, the diameter of the cylindrical advancing section can also be smaller than the diameter of the through hole on the slider fixing plate 5. The push rod 6 is inserted into the through hole of the slider fixing plate 5 and can slide horizontally. The front end face of the push rod 6 contacts the slider 4. The length of the push rod 6 in the slider fixing plate 5 is called the working length. When the push rod 6 presses against the slider 4, there is a gap between the tail baffle and the slider fixing plate 5. The push rod 6 is connected to the slider fixing plate 5 by the spring 7 and the bolt 8 passing through symmetrically arranged holes on the tail baffle. The tail baffle of the push rod 6 slides back and forth along the bolt 8, and the spring 7 presses against the tail baffle, generating a pushing force on the slider 4. Depending on the depth to which the bolt 8 is screwed in, the spring 7 is compressed to different degrees, and the elastic force applied to the slider 4 by the push rod 6 is also different, thereby limiting the reverse movement of the slider 4 due to the bending tendency of the loading area of ​​the sample 12.

[0059] The slider 4 is placed in the slider fixing plate 5, and the auxiliary slider 13 is inserted into the groove 14 and engages with the groove 14. The slider 4 must be able to slide to a certain extent in the slider fixing plate 5, and during the loading process, the slider 4 must always clamp the sample 12. When the transition area of ​​the sample 12 undergoes a thickness change under loading conditions, a gap is generated between the sample 12 and the slider 4. Under the action of the push rod 6, through the engagement of the auxiliary slider 13 and the groove 14, the slider 4 slides back and forth in the direction of the gap while moving up and down to eliminate the gap. That is, the slider 4 will adaptively slide along the auxiliary slider 13 under the action of the horizontal force of the push rod 6 to adhere to the sample 12, thereby continuously clamping the loading area of ​​the sample 12 throughout the entire loading process. Throughout the entire process, the comb-like structures at the upper and lower ends of the slider 4 are always engaged with the comb-like structures of the upper clamp 1 and the lower clamp 9.

[0060] The buckling prevention method using the aforementioned buckling-resistant device for cyclic tensile and compressive loading of differential thickness plate specimens during cyclic tensile and compressive loading specifically includes the following steps:

[0061] S1: As Figure 11As shown, a standard dog bone sample 12 was cut from an aluminum alloy differential thickness plate according to national standards. Figures 12-13 As shown, a differential thickness plate sample 12 was obtained, with a differential thickness ratio of 1:2, a transition zone length of 30 mm, a transition zone slope of 1:60, a parallel section gauge length of 25 mm, a clamping section of sample 12 being the equal thickness zone of the differential thickness plate, and a loading area of ​​sample 12 being the transition zone of the differential thickness plate, i.e., the parallel section of sample 12.

[0062] S2: Place the slider 4 into the slider fixing plate 5, and then place the loading area of ​​the sample 12 between the two slider fixing plates 5 so that the slider fixing plates 5 clamp the sample 12 along the thickness direction, ensuring that the contact surface between the slider 4 and the sample 12 is in complete contact. Use the fixing plate fastening bolt 10 and the fixing plate fastening nut 11 to connect the two slider fixing plates 5; put the push rod 6 into the slider fixing plate 5 and use the spring 7 and bolt 8 to tighten it. Adjust the degree of engagement of the bolt 8 so that the push rod 6 pushes against the slider 4.

[0063] S3: Fix the upper clamp 1 and the lower clamp 9 to the clamping section of the sample 12 respectively, leaving a 10mm clamping section at each end for the tensile testing machine to clamp the sample 12. The comb-like structure of the upper clamp 1 and the lower clamp 9 meshes with the comb-like structure at both ends of the slider 4 for 5mm.

[0064] S4: Place the remaining length of the specimen 12 in the clamping section where the lower clamp 9 is located into the lower clamp of the tensile testing machine and clamp it, and fix the position of the slider fixing plate 5; adjust the position of the upper clamp of the tensile testing machine so that it can just clamp the remaining length of the specimen 12 clamping section reserved at the upper end of the upper clamp 1.

[0065] S5: Through the program control of the tensile testing machine, strain / stress / displacement control mode can be adopted. Changing the tensile speed can change the cyclic tensile and compressive loading frequency, realizing the cyclic tensile and compressive loading of aluminum alloy differential thickness plates. After loading, the overall net shape of the specimen 12 does not change.

[0066] like Figure 14 The figure shows the results obtained from finite element simulation tests using the buckling-resistant device and method of the present invention. As can be seen from the curves, the aluminum alloy differential thickness plate specimen 12 obtained a smooth, distortion-free hysteresis loop under cyclic tensile and compressive loading. First, the specimen 12 was stretched to a strain of 0.8%, then unloaded and compressed in the opposite direction to a strain of -0.8%. After 10 cycles of cyclic tensile and compressive loading, the specimen 12 did not experience instability, and its net shape remained unchanged. Therefore, it is evident that the device and method provided by the present invention have good effects on cyclic tensile and compressive loading of aluminum alloy differential thickness plate specimens.

Claims

1. A buckling-resistant device for cyclic tensile and compressive loading of differential thickness plate specimens, characterized in that, include: The clamping assembly grips both ends of the sample; An anti-buckling component is disposed between the two gripping ends of the clamping assembly to constrain the transition zone of the specimen during loading. The buckling protection component includes: At least two sliders are symmetrically arranged on both sides of the transition zone of the sample, and each slider has a contact surface that is adapted to the surface of the transition zone of the sample. The elastic force application component, connected to the slider, is used to apply a continuous elastic force pointing towards the sample to the slider during cyclic tensile and compressive loading, so that the contact surface of the slider is always in close contact with the surface of the sample transition zone, thereby adaptively eliminating the gap caused by the change in sample thickness. The clamping assembly includes an upper clamp and a lower clamp, and the upper clamp and / or the lower clamp includes a pair of plate-shaped structural members arranged opposite each other; the end of the plate-shaped structural member connected to the anti-buckling component is provided with a groove that runs through the thickness direction to form a comb-shaped structure, and the end of the slider is provided with a comb-shaped structure that meshes with it. In the unloaded state, the meshing length is half the length of the comb. The elastic force application component includes: A slider fixing plate is disposed on the outside of the slider to accommodate and guide the slider to slide in a predetermined direction; At least one push rod: slidably mounted on the slider fixing plate, with the end of the push rod abutting against the slider; An elastic element is disposed between the front end of the push rod and the connecting bolt to provide elastic force; The slider and the slider fixing plate are connected by a mutually cooperating guide structure to guide the sliding direction of the slider; the guide structure includes auxiliary sliders that are inclined downward on both sides of the slider and a groove on the inner wall of the slider fixing plate; the auxiliary sliders and the grooves are both at an angle to the horizontal direction, and the angle of the angle is consistent with the slope of the sample transition zone.

2. The buckling prevention device for cyclic tensile and compressive loading of differential thickness plate specimens according to claim 1, characterized in that: The upper clamp is used to hold the first end of the sample, and the lower clamp is used to hold the second end of the sample.

3. The buckling prevention device for cyclic tensile and compressive loading of differential thickness plate specimens according to claim 2, characterized in that: Two plate-shaped structural members are connected by fasteners to clamp the ends of the specimen.

4. The buckling prevention device for cyclic tensile and compressive loading of differential thickness plate specimens according to claim 1, characterized in that: The auxiliary slider is slidably embedded in the groove, and the embedded length does not exceed 10mm.

5. The buckling prevention device for cyclic tensile and compressive loading of differential thickness plate specimens according to claim 1, characterized in that: The contact surface of the slider is an inclined plane, and the slope of the inclined plane is consistent with the slope of the sample transition zone.

6. A buckling-resistance method for cyclic tensile-compressive loading of a differential thickness plate specimen using the buckling-resistance device according to any one of claims 1 to 5, characterized in that, Specifically, the following steps are included: S1: Place the transition zone of the sample between at least two symmetrically arranged sliders, and make the contact surface of the sliders fit against the surface of the transition zone of the sample. S2: Apply a continuous elastic force, directed toward the sample direction, to the slider through the elastic force application component; S3: Clamp and fix both ends of the sample with the clamp assembly respectively; S4: Cyclic tensile and compressive loading is applied to the sample. During the loading process, the slider slides adaptively under the action of elastic force, so that the contact surface of the slider is always in close contact with the surface of the sample thickness change, thereby suppressing buckling deformation.

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