Biaxial tensile test sample loading and clamping device

Abstract

The utility model discloses a biaxial tensile test sample loading and clamping device, which comprises a loading platform and four clamping mechanisms, the loading platform is provided with a cross-shaped area for placing a cross-shaped flexible material sample, the four corners of the cross-shaped area are respectively provided with a boss, and the bosses are arranged on the loading platform. Clamp placement grooves are formed in the side edges of the loading platform and located at the four ends of the cross-shaped area, the upper ends of the clamp placement grooves and the ends, away from the cross-shaped area, of the clamp placement grooves are open, and each clamping mechanism is slidably inserted into the corresponding clamp placement groove and used for clamping the four ends of the flexible material sample. According to the utility model, the cross-shaped flexible material sample can be conveniently placed and positioned, the clamping mechanism can be conveniently inserted and mounted through the clamp mounting grooves formed in the four ends of the cross-shaped area, and meanwhile, the end part of the corresponding flexible material sample can be clamped by the clamping mechanism through the insertion mode between the clamp mounting grooves and the clamp mounting grooves, so that the flexible material sample can be conveniently clamped. And the loading platform can be conveniently dismounted, so that the influence of the loading platform on the test precision is avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of tensile test clamping devices, specifically to a biaxial tensile test sample loading and clamping device. Background Technology

[0002] Flexible materials have been widely used in soft robotics, morphing aircraft, and biomedical engineering in recent years. Accurate characterization of their mechanical properties is a crucial prerequisite for related designs. In practical applications, flexible materials are often subjected to complex stress-strain states, making it difficult to accurately and comprehensively characterize their mechanical properties using only uniaxial tensile tests. Therefore, it is necessary to conduct biaxial tensile tests.

[0003] When loading and installing conventional cruciform flexible materials on a testing machine, the material is usually placed directly into the fixture of the testing platform without alignment tools. This installation method is difficult to guarantee accuracy and is prone to unpredictable installation errors due to human factors, such as inaccurate sample alignment or sample skewing. These errors can cause unnecessary shearing of the sample during tensile testing, thus reducing the accuracy of the experimental results. In addition, the flexible material itself is relatively soft and prone to deformation during installation, further complicating sample loading and testing.

[0004] Therefore, there is an urgent need for a biaxial tensile test sample loading and clamping device to solve the problem of insufficient accuracy of conventional test fixtures when installing cross-shaped flexible materials. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a biaxial tensile test sample loading and clamping device to solve the problem of insufficient accuracy when conventional test clamps are used to install cross-shaped flexible materials.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A biaxial tensile test sample loading and clamping device is characterized by comprising a loading platform and four clamping mechanisms. The loading platform is provided with a cross-shaped area for placing a cross-shaped flexible material sample. Each of the four corners of the cross-shaped area is provided with a boss for positioning the flexible material sample. The sides of the loading platform and the four ends of the cross-shaped area are provided with clamp placement grooves. The upper end and the end away from the cross-shaped area of ​​the clamp placement groove are open. Each clamping mechanism is slidably inserted into a clamp placement groove and is used to clamp the four ends of the flexible material sample.

[0008] To optimize the above technical solution, the specific measures also include:

[0009] Furthermore, the clamping mechanism includes a lower clamp and an upper clamp. The lower clamp is slidably inserted into the clamp placement groove, and the upper clamp is used to detachably connect with the lower clamp. The lower clamp and the upper clamp are used to clamp the end of the flexible material sample.

[0010] Furthermore, the upper end of the lower clamp located in the clamp placement groove is flush with the cross-shaped area.

[0011] Furthermore, the lower clamp includes a lower clamp front end, a lower clamp rear end, and a lower clamp suspended connecting plate. The lower clamp front end is slidably inserted into the clamp placement groove. The lower clamp rear end is vertically connected upwards on the side of the lower clamp front end away from the loading platform, and the lower clamp suspended connecting plate is connected to the upper end of the lower clamp rear end on the side away from the lower clamp front end. The lower clamp front end is detachably connected to the upper clamp, and the lower clamp suspended connecting plate is detachably connected to an external tensioning mechanism.

[0012] Furthermore, the stretching mechanism includes an adapter plate and a stretching shaft. The adapter plate is used to be detachably connected to the lower clamp suspension connecting plate, and the stretching shaft is used to connect to and drive the adapter plate to perform stretching motion.

[0013] Furthermore, the lower clamp suspended connecting plate is provided with a vertical third connecting hole, and the upper end of the adapter plate is provided with a vertical fourth connecting hole. The lower clamp suspended connecting plate and the adapter plate are detachably connected by bolts to connect the third connecting hole and the fourth connecting hole.

[0014] Furthermore, the lower clamp has symmetrical vertical first connecting holes on both sides of its front end, and the upper clamp has corresponding second connecting holes. The front end of the lower clamp and the upper clamp are detachably connected by bolts to the first connecting holes and the second connecting holes.

[0015] Furthermore, the upper end face of the front end of the lower clamp and the lower end face of the upper clamp are respectively provided as toothed surfaces that can mesh with each other.

[0016] Furthermore, the angle between the long side and the short side of the serration on the tooth surface is 90°, and the angle between the short side and the vertical direction is 27°.

[0017] Furthermore, the depth of the serrations on the tooth surface is 0.279 mm, and the size of the serrations projected in the horizontal direction is 0.711 mm.

[0018] The beneficial effects of this utility model are:

[0019] This invention utilizes a loading platform structure with a cross-shaped area and protrusions to facilitate the placement and positioning of cross-shaped flexible material samples. Clamping slots at the four ends of the cross-shaped area allow for easy insertion and installation of the clamping mechanism. This insertion method allows the clamping mechanism to be mounted on the testing platform's tension shaft after clamping the end of the corresponding flexible material sample, and then easily removed from the loading platform. This avoids the loading platform affecting experimental accuracy and solves the problem of inaccurate installation of cross-shaped flexible materials using conventional experimental fixtures. It achieves aligned, convenient, and reliable clamping and installation, increasing the convenience of the experiment while ensuring its accuracy.

[0020] The loading platform and other components in this utility model device can all be made using low-cost 3D printing technology. The cross-shaped area on the loading platform can be replaced or designed as needed according to the shape or style of different flexible material samples. Then, the design structure can be printed and formed. The operation is convenient and the testing cost is low.

[0021] This invention clamps flexible material samples using upper and lower clamps, securing them with screws or bolts to achieve tight clamping. Simultaneously, the toothed surfaces in the upper and lower clamps increase friction between the horizontal surfaces and the flexible material sample, reducing slippage during loading and ensuring sufficient preload even after sample deformation. For sample installation, a boss on the loading platform precisely positions the sample, preventing installation errors caused by human intervention. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a biaxial tensile test sample loading and clamping device proposed in this utility model.

[0023] Figure 2 This is an exploded view of the overall structure of a biaxial tensile test sample loading and clamping device proposed in this utility model;

[0024] Figure 3 This is a schematic diagram of the loading platform of a biaxial tensile test sample loading and clamping device proposed in this utility model;

[0025] Figure 4 This is a schematic diagram of the lower clamp of a biaxial tensile test sample loading and clamping device proposed in this utility model;

[0026] Figure 5This is a schematic diagram of the structure of the adapter plate of the biaxial tensile test sample loading and clamping device proposed in this utility model;

[0027] Figure 6 This is a schematic diagram of a biaxial tensile test sample loading and clamping device proposed in this utility model.

[0028] Reference numerals: 1. Loading platform; 11. Boss; 12. Fixture mounting slot; 2. Flexible material sample; 3. Lower fixture; 31. Front end of lower fixture; 32. Rear end of lower fixture; 33. Suspended connecting plate of lower fixture; 4. Upper fixture; 5. Adapter plate; 6. Tensioning shaft. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings.

[0030] As attached Figure 1 and attached Figure 3 As shown, a biaxial tensile test sample loading and clamping device according to an embodiment of the present invention includes a loading platform 1 and four clamping mechanisms. The loading platform 1 is provided with a cross-shaped area for placing a cross-shaped flexible material sample 2. The shape of the cross-shaped area can match the shape of the flexible material sample 2. At each of the four corners of the cross-shaped area, there is an arc-shaped protrusion 11 for positioning the flexible material sample 2. The side of the loading platform 1 and the four ends of the cross-shaped area are provided with clamp placement grooves 12. The upper end and the end away from the cross-shaped area of ​​the clamp placement groove 12 are open. The four clamping mechanisms are respectively distributed in a cross shape, and each clamping mechanism is slidably inserted into a clamp placement groove 12 and is used to clamp the four ends of the flexible material sample 2.

[0031] This invention, through the structural design of the loading platform 1, utilizes the cross-shaped area on the loading platform 1 in conjunction with the boss 11 to facilitate the placement and positioning of the cross-shaped flexible material sample 2. The clamping slots 12 located at the four ends of the cross-shaped area allow for convenient insertion and installation of the clamping mechanism. Furthermore, the insertion method allows for easy removal of the loading platform 1 after the clamping mechanism has clamped the end of the corresponding flexible material sample 2, thus avoiding any impact of the loading platform 1 on experimental accuracy. This solves the problem of insufficient accuracy in conventional experimental clamps when installing cross-shaped flexible materials, achieving aligned, convenient, and reliable clamping and installation, increasing the convenience of the experiment, and ensuring experimental accuracy.

[0032] The loading platform 1 and other components in this utility model device can all be made using low-cost 3D printing technology. The cross-shaped area on the loading platform 1 can be replaced or designed according to the shape or style of different flexible material samples 2 as needed, and then printed according to the design structure. The operation is convenient and the test cost is low.

[0033] As attached Figure 2 As shown, in a specific embodiment based on the above, the clamping mechanism includes a lower clamp 3 and an upper clamp 4. The lower clamp 3 is slidably inserted into the clamp placement groove 12, and the upper clamp 4 is used for detachable connection with the lower clamp 3. The lower clamp 3 and the upper clamp 4 are used to clamp the end of the flexible material sample 2. In use, the end of the flexible material sample 2 is positioned as a clamping arm between the lower clamp 3 and the upper clamp 4. Both the upper clamp 4 and the lower clamp 3 are 3D printed from resin material, ensuring good precision.

[0034] The upper end of the lower clamp 3, located in the clamp placement groove 12, is flush with the cross-shaped area. This allows for convenient positioning and clamping of the flexible material sample 2.

[0035] As attached Figure 4 As shown, in another specific embodiment based on the above, the lower clamp 3 includes a lower clamp front end 31, a lower clamp rear end 32, and a lower clamp suspended connecting plate 33. The lower clamp front end 31 is used to slide into the clamp placement groove 12. The lower clamp rear end 32 is vertically connected to the side of the lower clamp front end 31 away from the loading platform 1. The lower clamp suspended connecting plate 33 is connected to the upper end of the lower clamp rear end 32 and the side away from the lower clamp front end 31. The lower clamp front end 31 is used to detachably connect to the upper clamp 4. The lower clamp suspended connecting plate 33 is used to detachably connect to the external tensioning mechanism.

[0036] As attached Figure 5 and attached Figure 6 As shown, the stretching mechanism includes a transition plate 5 and a stretching shaft 6. The transition plate 5 is used to be detachably connected to the lower clamp suspension connecting plate 33, and the stretching shaft 6 is used to connect to and drive the transition plate 5 to perform stretching motion.

[0037] The lower clamping suspension connecting plate 33 has a vertical third connecting hole, and the upper end of the adapter plate 5 has a vertical fourth connecting hole. The lower clamping suspension connecting plate 33 and the adapter plate 5 are detachably connected by bolts to connect the third and fourth connecting holes. Both the third and fourth connecting holes are threaded holes, and two sets can be provided as needed. In this design, the side of the adapter plate 5 can be connected to the tension shaft 6 via set screws.

[0038] The lower clamp 31 has symmetrical vertical first connecting holes on both sides, and the upper clamp 4 has corresponding second connecting holes. The lower clamp 31 and the upper clamp 4 are detachably connected by bolts to the first and second connecting holes. Both the first and second connecting holes are threaded holes. Two sets of the first and second connecting holes can be provided as needed, with two holes in each set, and they are symmetrically arranged about the axis of the tension shaft 6.

[0039] In the above scheme, the upper surface of the front end 31 of the lower clamp and the axis of the tension shaft 6 are located in the first plane, and the first plane is parallel to the plane of the flexible material sample 2; the central symmetry plane of the upper clamp 4, the central symmetry plane of the corresponding lower clamp 3, the central symmetry plane of the corresponding adapter plate 5 and the axis of the corresponding tension shaft 6 are located in the second plane, and the second plane is perpendicular to the plane of the flexible material sample 2.

[0040] In another specific embodiment based on the above, the upper end face of the lower clamp front end 31 and the lower end face of the upper clamp 4 are respectively set as toothed surfaces that can mesh with each other.

[0041] The angle between the long and short sides of the serrations on the tooth surface is 90°, and the angle between the short side and the vertical direction is 27°. The depth of the serrations on the tooth surface is 0.279 mm, and the size of the serrations projected in the horizontal direction, i.e., the spacing between the serrations, is 0.711 mm.

[0042] This invention clamps the flexible material sample 2 using an upper clamp 4 and a lower clamp 3, securing them together with screws or bolts to achieve a tight connection. Simultaneously, the toothed surfaces of the upper clamp 4 and lower clamp 3 increase friction between the horizontal surfaces of the clamps and the flexible material sample 2, reducing slippage during loading and ensuring sufficient preload even after deformation. For the installation of the flexible material sample 2, the boss 11 on the loading platform 1 precisely positions the sample, preventing installation errors caused by human error.

[0043] One specific embodiment of this utility model includes the following steps:

[0044] Step 1: Place the lower clamp 3 in the clamp placement slot 12, place the flexible material sample 2 in the cross-shaped area of ​​the loading platform 1 to complete the positioning of the flexible material sample 2, and place the clamping arm of the flexible material sample 2 on the lower clamp 3.

[0045] Step 2: Set the upper clamp 4 and the lower clamp 3 accordingly, and use the upper clamp 4 and the lower clamp 3 to cooperate and press the flexible material sample 2. The upper clamp 4 and the lower clamp 3 are fastened together by screws to achieve the clamping of the flexible material sample 2.

[0046] Step 3: Manually lift the loading platform 1 and connect the lower clamp suspension connecting plate 33 of the lower clamp 3 to the adapter plate 5 with screws. At this time, the adapter plate 5 is connected to the tensile shaft 6 of the biaxial tensile test bench.

[0047] Step four: Remove the loading platform 1 from under the sample 2 to complete the installation of the flexible material sample 2 on the biaxial tensile test platform, and conduct subsequent tests as needed.

[0048] It should be noted that the terms such as "upper", "lower", "left", "right", "front", and "back" used in this utility model are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0049] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should be considered within its protection scope.

Claims

1. A biaxial tensile specimen loading and clamping device, characterized by: The device comprises a loading platform (1) and four clamping mechanisms, the loading platform (1) is provided with a cross-shaped area for placing a cross-shaped flexible material sample (2), four corners of the cross-shaped area are provided with bosses (11) for positioning the flexible material sample (2), the side edges of the loading platform (1) and the four ends of the cross-shaped area are provided with clamp installation grooves (12), the upper end and the end away from the cross-shaped area of each clamp installation groove (12) are open, each clamping mechanism is respectively slidably inserted into one clamp installation groove (12) and is used for clamping four ends of the flexible material sample (2).

2. The biaxial tensile specimen loading and clamping device according to claim 1, characterized in that: The clamping mechanism comprises a lower clamp (3) and an upper clamp (4), the lower clamp (3) is slidably inserted into the clamp installation groove (12), the upper clamp (4) is used for detachably connecting with the lower clamp (3), and the lower clamp (3) and the upper clamp (4) are used for clamping the end of the flexible material sample (2) therebetween.

3. The biaxial tensile specimen loading and clamping device according to claim 2, characterized in that: The upper end of the lower clamp (3) in the clamp installation groove (12) is flush with the cross-shaped area.

4. The biaxial tensile specimen loading and clamping device according to claim 2, characterized in that: The lower clamp (3) comprises a lower clamp front end (31), a lower clamp rear end (32) and a lower clamp overhanging connecting plate (33), the lower clamp front end (31) is used for being slidably inserted into the clamp installation groove (12), the lower clamp rear end (32) is vertically connected to the side of the lower clamp front end (31) away from the loading platform (1) and upward, and the upper end of the lower clamp rear end (32) and the side of the lower clamp rear end (32) away from the lower clamp front end (31) are connected with the lower clamp overhanging connecting plate (33), the lower clamp front end (31) is used for detachably connecting with the upper clamp (4), and the lower clamp overhanging connecting plate (33) is used for detachably circumscribing a stretching mechanism.

5. The biaxial tensile specimen loading and clamping device according to claim 4, characterized in that: The stretching mechanism comprises an adapter plate (5) and a stretching shaft (6), the adapter plate (5) is used for detachably connecting with the lower clamp overhanging connecting plate (33), and the stretching shaft (6) is used for connecting and driving the adapter plate (5) to perform a stretching movement.

6. A biaxial tensile specimen loading and clamping device according to claim 5, characterized in that: The lower clamp overhanging connecting plate (33) is provided with a vertical third connecting hole, the upper end of the adapter plate (5) is provided with a vertical fourth connecting hole, and the lower clamp overhanging connecting plate (33) and the adapter plate (5) are detachably connected through bolt screwing of the third connecting hole and the fourth connecting hole.

7. The biaxial tensile specimen loading and clamping device according to claim 4, characterized in that: The lower clamp front end (31) is symmetrically provided with vertical first connecting holes on both sides, and the upper clamp (4) is correspondingly provided with second connecting holes, and the lower clamp front end (31) and the upper clamp (4) are detachably connected through bolt screwing of the first connecting holes and the second connecting holes.

8. The biaxial tensile specimen loading and clamping device according to claim 4, characterized in that: The upper end surface of the lower clamp front end (31) and the lower end surface of the upper clamp (4) are correspondingly provided as tooth surfaces capable of being engaged with each other.

9. The biaxial tensile specimen loading and clamping device according to claim 8, characterized in that: The included angle between the long side and the short side of the sawtooth on the tooth surface is 90°, and the included angle between the short side and the vertical direction is 27°.

10. The biaxial tensile specimen loading and clamping device of claim 8, wherein: The depth of the sawtooth on the tooth surface is 0.279 mm, and the size of the sawtooth projected in the horizontal direction is 0.711 mm.

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