Equal biaxial tensile test clamp and test machine for elastomer plate

Abstract

The utility model discloses an isobiaxial tensile test fixture and testing machine for an elastomer plate, and the isobiaxial tensile test fixture comprises: a clamping assembly for clamping a to-be-tested sample and at least having a chuck, one end of the chuck clamping the to-be-tested sample, and the other end of the chuck being connected with a tensile assembly; the stretching assembly is used for stretching the to-be-tested sample and at least provided with a winding wire, the first end of the winding wire is connected with the chuck of the clamping assembly, and the second end is connected with the transmission assembly; the transmission assembly is used for applying tension to the to-be-tested sample and at least provided with a movable plate and a transmission screw rod, the transmission screw rod is installed on the testing machine, the center of the movable plate is installed on the transmission screw rod and can move up and down along with transmission of the transmission screw rod, and the outer side of the movable plate is connected with the second end of the winding wire to drive the winding wire to move; the tension is transmitted to the chuck connected with the first end of the winding wire, and the to-be-tested sample is stretched for testing. According to the scheme, test errors caused by the thickness of the to-be-tested sample and friction force are eliminated, and very consistent and accurate elastomer uniaxial compression strain state data can be provided.

Description

Technical Field

[0001] The utility model relates to the field of new material testing equipment, and particularly relates to an equal biaxial tensile test fixture and testing machine for an elastomer plate. Background Art

[0002] The performance of elastomer materials is usually obtained through three strain states, namely: uniaxial tension, uniaxial compression, and pure shear. Among them, the uniaxial tension state is easily satisfied, and the pure shear state can be obtained through a plane tensile test with excellent repeatability accuracy. However, in the uniaxial compression test, friction will be generated between the pressure plate and the specimen, and the friction will change with the increase of the compression load, resulting in a mixed strain state including tension, compression, and shear in the uniaxial compression test, which will cause obvious errors in the test results. Therefore, how to test the uniaxial compression strain state of elastomer materials has become an urgent problem to be solved.

[0003] Therefore, in view of the above defects, it is necessary to improve the existing technology. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome at least one defect of the existing technology and provide an equal biaxial tensile test fixture and testing machine for an elastomer plate.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An equal biaxial tensile test fixture for an elastomer plate, comprising:

[0007] A clamping assembly for clamping a specimen to be tested, the clamping assembly having at least a chuck, one end of the chuck clamping the specimen to be tested, and the other end connecting to a stretching assembly;

[0008] A stretching assembly for stretching the specimen to be tested, the stretching assembly having at least a winding wire, the first end of the winding wire connecting to the chuck of the clamping assembly, and the second end connecting to a transmission assembly;

[0009] A transmission assembly for applying a tensile force to the specimen to be tested, the transmission assembly having at least a movable plate and a transmission lead screw, the transmission lead screw being installed on the testing machine, the center of the movable plate being installed on the transmission lead screw and capable of moving up and down with the transmission of the transmission lead screw, the outside of the movable plate being connected to the second end of the winding wire to drive the winding wire to move, so as to transmit the tensile force to the chuck connected to the first end of the winding wire and stretch the specimen to be tested for testing.

[0010] Furthermore, the clamping assembly has a clamping head, the clamping head has an upper clamping plate and a lower clamping plate, the upper clamping plate and the lower clamping plate both have a first clamping plate end, a connecting column is arranged opposite to the first clamping plate end of the upper clamping plate and the first clamping plate end of the lower clamping plate, the sample to be tested is located between the connecting columns of the upper clamping plate and the lower clamping plate, and is clamped by the connecting columns.

[0011] Furthermore, the upper clip and the lower clip both have a second clip end, the second clip end is far away from the first clip end, a winding connecting rod is passed through the second clip end of the upper clip and the second clip end of the lower clip, and the first end of the winding clip is connected between the second clip end of the upper clip and the second clip end of the lower clip.

[0012] Furthermore, the stretching assembly has at least a test bench, a pad is provided in the middle of the test bench, the clamping assembly is installed at the periphery of the pad, a winding bracket is provided on the test bench outside the pad, the winding bracket is arranged corresponding to the clamping assembly, and the winding is wound on the winding bracket.

[0013] Furthermore, the winding bracket has at least a base, which is an inverted π-shaped structure, with a horizontal base and two vertical side panels. The winding bracket is fixed to the test bench through the base, and a rotatable winding wheel is supported between the two side panels by a screw, and the winding wire is wound on the winding wheel.

[0014] Furthermore, the transmission assembly has at least a movable plate, which is located below the test bench and has a center hole. The transmission screw passes through the movable plate and extends upward to the center of the test bench to ensure the center coaxiality of the movable plate when the transmission screw moves up and down. A high-precision force sensor is also provided at the connection between the transmission screw and the movable plate to detect the total force value transmitted to the movable plate by the clamping assembly. A fixing piece is provided outside the center hole of the movable plate, and the second end of the winding is connected to the fixing piece.

[0015] Furthermore, the fixing member is arranged corresponding to the winding bracket and the clamping assembly.

[0016] Furthermore, the movable plate is provided with a guide hole, a guide column is passed through the guide hole, two ends of the guide column are respectively connected to the test bench and the test machine, and are arranged parallel to the transmission screw.

[0017] This solution also relates to a testing machine, which has a main testing machine body. The main testing machine body has a housing. The equal biaxial tensile test fixture for the elastomer plate is installed above the housing. There is a motor inside the housing of the main testing machine body. The motor is connected to the bottom end of the transmission lead screw of the equal biaxial tensile test fixture for the elastomer plate, and drives the transmission lead screw to drive the movable plate to move up and down.

[0018] Furthermore, a bracket is vertically arranged above the housing of the main testing machine body. An extensometer holder is arranged on the bracket. A video extensometer is installed on the extensometer holder. The video extensometer lens is located directly above the specimen to be tested. This video extensometer is a non-contact extensometer, which is used to observe and record the change of the middle gauge length of the specimen to be tested. Through software, the change curves of various data such as force, displacement, and strain of the elastomer material during the tensile process are obtained, and various performance parameters of the elastomer material in the equal biaxial tensile strain state are calculated.

[0019] Based on the above-mentioned equal biaxial tensile test fixture for the elastomer plate and the testing machine, the following beneficial effects are achieved:

[0020] (1) In this solution, the equal biaxial tensile strain state of the elastomer material can be equivalent to the uniaxial compression strain state, and it is not affected by the radial position and thickness of the specimen, eliminating the test errors caused by the thickness and friction of the specimen to be tested, and obtaining consistent and accurate data of the uniaxial compression strain state of the elastomer.

[0021] (2) Through the setting of the guide posts and the transmission lead screw in this solution, the central coaxiality during the up and down movement of the movable plate is effectively guaranteed.

[0022] (3) In this solution, the tension of the flexible winding can be adjusted through the stretching assembly to ensure that the radial forces received by the specimen to be tested in each clamping direction are consistent.

[0023] (4) In this solution, a high-precision force value sensor is used to measure the total force value transmitted from multiple clamping assemblies to the movable plate, and the data display is intuitive and accurate.

[0024] (5) In this solution, the change of the middle gauge length of the specimen to be tested is observed and recorded through a non-contact extensometer. Through software, the change curves of various data such as force, displacement, and strain of the elastomer material during the tensile process are obtained, and various performance parameters of the elastomer material in the equal biaxial tensile strain state are calculated. Description of the Drawings

[0025] Figure 1 is the structural schematic diagram of the specimen to be tested in this embodiment;

[0026] Figure 2 is Figure 1 the finite element modeling of the specimen to be tested;

[0027] Figure 3 is Figure 2 Static analysis;

[0028] Figure 4 is the structural schematic diagram of the test machine in this embodiment;

[0029] Figure 5 is the structural schematic diagram of the equal biaxial tensile test fixture in this embodiment;

[0030] Figure 6 is Figure 5 Side view structural schematic diagram;

[0031] Figure 7 is Figure 5 Top view structural schematic diagram;

[0032] Figure 8 is the combined structural schematic diagram of the clamping assembly in this embodiment;

[0033] Figure 9 is Figure 8 The structural schematic diagram of any one of the clamping assemblies;

[0034] Figure 10 is the structural schematic diagram of the movable plate in this embodiment;

[0035] Figure 11 is the installation schematic diagram of the motor and the equal biaxial tensile test fixture in the test machine of this embodiment;

[0036] In the figure:

[0037] 1 - Specimen to be tested, 10 - Through hole, 11 - Groove;

[0038] 2 - Test machine, 20 - Equal biaxial tensile test fixture, 200 - Clamping assembly, 2000 - Chuck, 20000 - Upper clamping piece, 200000 - First end of the clamping piece, 200001 - Second end of the clamping piece, 20001 - Lower clamping piece, 2001 - Connecting column, 2002 - Gasket, 2003 - Wire winding connecting rod, 201 - Tensile assembly, 2010 - Test bench,

[0039] 2011 - Spacer block, 2012 - Wire winding bracket, 20120 - Base, 20121 - Side plate, 20122 - Screw rod, 2013 - Wire winding, 20130 - First end, 20131 - Second end, 2014 - Wire winding wheel, 202 - Transmission assembly, 2020 - Movable plate, 20200 - Central hole, 20201 - Guide hole, 2021 - Transmission lead screw, 2022 - Guide post, 2023 - Fixed part, 21 - Test mainframe, 210 - Housing, 211 - Motor, 212 - Control box, 213 - Motor mounting part, 22 - Bracket, 220 - Track, 221 - Extensometer bracket, 23 - Video extensometer. Detailed implementation mode

[0040] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0041] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0042] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above the", and "on the" second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "below the", and "under the" second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal height than the second feature.

[0043] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present utility model.

[0044] The equal biaxial tensile test fixture 20 and the testing machine 2 for the elastomer plate in this embodiment are used to complete the equal biaxial tensile test of the elastomer plate, and are particularly suitable for the test of a disc-shaped elastomer specimen. For the elastomer plate used as the specimen 1 to be tested in this embodiment, such as Figure 1As shown, it is a circular plate structure with a number of through holes 10 evenly distributed around the circumference. A number of through holes 10 are all connected to a cut groove 11. By setting the through holes 10 and the cut groove 11, the tearing of the test specimen 1 during the clamping and stretching process can be reduced. In addition, due to the particularity of the test method of this embodiment, to avoid the influence of the friction of the clamping assembly 200 on the surface deformation of the test specimen 1, by clamping the outer circle (the edges of the through holes 10 and the cut groove 11), the stress of the test specimen 1 itself is dispersed to the inner circle to achieve the purpose of uniform force distribution.

[0045] As Figure 2 is for Figure 1 the finite element model of the test specimen 1 shown. After finite element modeling, through finite element analysis and simulation testing, the static analysis diagram shown in Figure 3 is obtained. It is found that: the elastomeric material in the equibiaxial tensile strain state can be equivalent to the uniaxial compressive strain state and is not affected by the radial position and thickness of the specimen. Therefore, based on the above test analysis, the equibiaxial tensile test is adopted in the testing machine of this embodiment to measure various performance parameters of the elastomeric plate in the tensile strain state.

[0046] Based on the above test specimen 1, an equibiaxial tensile test fixture 20 for an elastomeric plate in this embodiment includes:

[0047] A clamping assembly 200 for clamping the test specimen 1. The clamping assembly 200 has at least a chuck 2000. One end of the chuck 2000 clamps the test specimen 1, and the other end is connected to a stretching assembly 201;

[0048] A stretching assembly 201 for stretching the test specimen 1. The stretching assembly 201 has at least a winding wire 2013. The first end 20130 of the winding wire 2013 is connected to the chuck 2000 of the clamping assembly 200, and the second end 20131 is connected to a transmission assembly 202;

[0049] A transmission assembly 202 for applying a tensile force to the test specimen 1. The transmission assembly 202 has at least a movable plate 2020 and a transmission lead screw 2021. The transmission lead screw 2021 is installed on the testing machine. The center of the movable plate 2020 is installed on the transmission lead screw 2021 and can move up and down with the transmission of the transmission lead screw 2021. The outside of the movable plate 2020 is connected to the second end 20131 of the winding wire 2013 to drive the winding wire 2013 to move, so as to transfer the tensile force to the chuck 2000 connected to the first end 20130 of the winding wire 2013 and stretch the test specimen 1 for testing.

[0050] A more specific description is as follows:

[0051] This embodiment has a clamping assembly 200 for clamping the specimen 1 to be tested. Since the specimen 1 to be tested is a circular plate-like structure, the clamping assemblies 200 are evenly distributed around the outer circle of the specimen 1 to be tested. More specifically, the clamping assemblies 200 are evenly distributed outside the through hole 10 of the specimen 1 to be tested and are located between two adjacent cutting grooves 11; the clamping assembly 200 has a chuck 2000, and the chuck 2000 has an upper clamping piece 20000 and a lower clamping piece 20001. Both the upper clamping piece 20000 and the lower clamping piece 20001 have a first clamping piece end 200000. A connecting column 2001 is oppositely arranged between the first clamping piece end 200000 of the upper clamping piece 20000 and the first clamping piece end 200000 of the lower clamping piece 20001. The specimen 1 to be tested is located between the connecting columns 2001 of the upper clamping piece 20000 and the lower clamping piece 20001 and is clamped by the connecting column 2001.

[0052] In this embodiment, a gasket 2002 is further arranged between the connecting column 2001 and the upper clamping piece 20000 and the lower clamping piece 20001. The area of the gasket 2002 is larger than the area of the bottom of the connecting column 2001, effectively increasing the contact area between the clamping assembly 200 and the specimen 1 to be tested and ensuring the firmness of clamping.

[0053] In this embodiment, both the upper clamping piece 20000 and the lower clamping piece 20001 have a second clamping piece end 200001. The second clamping piece end 200001 is far from the first clamping piece end 200000. A winding connecting rod 2003 is threaded between the second clamping piece end 200001 of the upper clamping piece 20000 and the second clamping piece end 200001 of the lower clamping piece 20001. The first clamping piece end 200000 of the winding 2013 is connected between the second clamping piece end 200001 of the upper clamping piece 20000 and the second clamping piece end 200001 of the lower clamping piece 20001.

[0054] It should be noted that in this solution, the upper clamping piece 20000 and the lower clamping piece 20001 have the same structure, and the width of the first clamping piece end 200000 is smaller than the width of the second clamping piece end 200001. In other embodiments, the upper clamping piece 20000 and the lower clamping piece 20001 can be set to be not completely the same, and the widths of both ends of the upper clamping piece 20000 and the lower clamping piece 20001 can also be the same or the width of the first clamping piece end 200000 is greater than the width of the second clamping piece end 200001.

[0055] In this embodiment, the stretching assembly 201 at least has a test bench 2010, which is also arranged as a circular plate-like structure based on the circular plate-like structure of the specimen 1 to be tested. The test bench 2010 and the specimen 1 to be tested are concentrically arranged, and the radius of the test bench 2010 is greater than the radius of the specimen 1 to be tested. A cushion block 2011 is fixedly arranged in the circular middle part of the test bench 2010. The cushion block 2011 is also arranged as a circular plate-like structure concentric with the test bench 2010. The clamping assembly 200 is installed above the cushion block 2011 and is evenly arranged at the outer circumference of the cushion block 2011. Based on the structure of this embodiment, the specimen 1 to be tested, the cushion block 2011, and the test bench 2010 in this solution are arranged in sequence from top to bottom.

[0056] A wire winding bracket 2012 is arranged on the circumferential part of the test bench 2010 that exceeds the cushion block 2011. The wire winding brackets 2012 are evenly arranged on the test bench 2010 and are arranged corresponding to the clamping assembly 200. The wire winding 2013 is wound around the wire winding bracket 2012. For a more detailed description, the wire winding bracket 2012 at least has a base, and the base has an inverted π-shaped structure, with a horizontal base 20120 and two vertical side plates 20121. The wire winding bracket 2012 is fixed on the test bench 2010 through the base 20120. A rotatable wire winding wheel 2014 is supported between the two side plates 20121 by a screw 20122, and the wire winding 2013 is wound around the wire winding wheel 2014.

[0057] In this embodiment, the transmission assembly 202 at least has a movable plate 2020. The movable plate 2020 is located below the test bench 2010 and has a central hole 20200. The transmission lead screw 2021 passes through the movable plate 2020 and extends upward to the center of the test bench 2010. More specifically, the transmission lead screw 2021 has a transmission shaft and a sleeve sleeved on the transmission shaft that can displace as the transmission shaft rotates. The central hole 20200 of the movable plate 2021 is arranged in cooperation with the sleeve. The upper end of the transmission shaft passes through the movable plate 2020 and is fixed at the center of the test bench 2021, so as to realize the displacement of the movable plate 2020 between the test bench 2010 and the test main machine 21 along the rotation of the transmission shaft. A high-precision force value sensor (not shown in the drawings) is also arranged at the connection between the transmission lead screw 2021 and the movable plate 2020 to detect the total force value transmitted from the clamping assembly 200 to the movable plate 2020. The movable plate 2020 also has a guide hole 20201, and a guide post 2022 is inserted into the guide hole 20201. The two ends of the guide post 2022 are respectively connected to the test bench 2010 and the test main machine 21 and are arranged parallel to the transmission lead screw 2021 to ensure the central coaxiality when the movable plate 2020 moves up and down along with the transmission lead screw 2021. In this embodiment, the guide post 2022 adopts a four-column structure. In other embodiments, the guide post 2022 can also be set to other numbers.

[0058] A fixing member 2023 is provided outside the central hole 20200 of the movable plate 2020. The second end 20131 of the winding wire 2013 is connected to the fixing member 2023. The fixing member 2023 is correspondingly arranged with the winding bracket 2012 and the clamping assembly 200. In this embodiment, the fixing member 2023 adopts a fixing screw. In other embodiments, the fixing member 2023 can also adopt structures such as a hook body structure and a clamping structure to fixedly connect with the second end 20131 of the winding wire 2013. By adjusting the tightness of the flexible winding wire, it can be ensured that the radial forces received by the specimen to be tested 1 in each clamping direction are consistent. The total force value transmitted from the clamping assembly 200 to the movable plate 2020 is measured by a high-precision force value sensor, and the data display is intuitive and accurate.

[0059] This embodiment also relates to a testing machine 2. The testing machine 2 has a test main body 21. The test main body 21 has a housing 210. The equal biaxial tensile test fixture 20 for the elastomer plate is installed above the housing 210. A motor 211 is provided in the housing 210 of the test main body 21. The motor 211 is connected to the bottom end of the transmission lead screw 2021 of the equal biaxial tensile test fixture 20 for the elastomer plate. Specifically, the motor 211 is connected to the bottom end of the transmission shaft of the transmission lead screw 2021, directly driving the transmission shaft to rotate, and then driving the movable plate 2020 connected to the shaft sleeve to move up and down.

[0060] In this embodiment, the test main body 21 of the testing machine 2 has two parts. One part is the motor installation part 213, and the other part is the control box 212. The control box 212 is electrically connected to the motor installation part 213. The output end of the motor 211 is connected to the bottom of the transmission lead screw 2021. The transmission lead screw 2021 in this embodiment adopts a ball screw.

[0061] A bracket 22 is vertically provided above the housing 210 of the test main body 21. The bracket 22 is fixed to the housing 210 through an L-shaped plate. An extensometer holder 221 is provided on the bracket 22. A video extensometer 23 is installed on the extensometer holder 221. The lens of the video extensometer 23 is located directly above the specimen to be tested 1. It should be noted here that a track 220 can also be provided on the bracket 22. When the extensometer holder 221 is installed on the bracket 22, it can move up and down along the track 220 to adjust the distance between the video extensometer 23 and the specimen to be tested 1. The video extensometer 23 is a non-contact extensometer, and the video extensometer 23 itself can adopt an existing video extensometer 23 for observing and recording the change of the middle gauge length of the specimen to be tested 1.

[0062] Based on the above-mentioned biaxial tensile test fixture and testing machine for elastomer plates, after the test starts, the movable plate 2020 is driven by the motor 211 and the transmission lead screw 2021 to move downward at a constant speed. The winding 2013 generates a radial displacement on the clamping assembly 200 of the specimen to be tested 1, so that a uniform radial tensile force is generated around the disc-shaped specimen to be tested 1, making the specimen to be tested 1 reach the strain state of biaxial tension. The non-contact extensometer directly above the specimen to be tested 1 observes and records the change of the middle gauge length of the specimen. Through software, the change curves of various data such as force, displacement, and strain of the elastomer material during the tensile process are obtained, and various performance parameters of the elastomer material in the biaxial tensile strain state are calculated.

[0063] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An equibiaxial tensile test fixture for an elastic plate, characterized in that: include: A clamping assembly, used for clamping the sample to be tested, the clamping assembly at least comprising a clamp, one end of the clamp clamps the sample to be tested, and the other end is connected to the stretching assembly; A stretching assembly, used for stretching the sample to be tested, wherein the stretching assembly at least comprises a winding wire, a first end of the winding wire is connected to the clamp of the clamping assembly, and a second end of the winding wire is connected to a transmission assembly; A transmission assembly is used to apply tension to the sample to be tested. The transmission assembly has at least a movable plate and a transmission screw. The transmission screw is installed on the testing machine. The center of the movable plate is installed on the transmission screw and can move up and down with the transmission of the transmission screw. The outer side of the movable plate is connected to the second end of the winding wire to drive the winding wire to move, so as to transfer the tension to the chuck connected to the first end of the winding wire, thereby stretching the sample to be tested for testing.

2. The equibiaxial tensile test fixture for elastic plates according to claim 1, characterized in that: The clamping assembly comprises a clamping head, wherein the clamping head comprises an upper clamping piece and a lower clamping piece, wherein the upper clamping piece and the lower clamping piece both comprise a first clamping piece end, and a connecting column is arranged opposite to the first clamping piece end of the upper clamping piece and the first clamping piece end of the lower clamping piece, and the sample to be tested is located between the connecting columns of the upper clamping piece and the lower clamping piece, and is clamped by the connecting columns.

3. The equibiaxial tensile test fixture for elastic plates according to claim 2, characterized in that: The upper clip and the lower clip both have a second clip end, the second clip end is far away from the first clip end, a winding connecting rod is passed through the second end of the upper clip and the second clip end of the lower clip, and the first end of the winding clip is connected between the second end of the upper clip and the second end of the clip of the lower clip.

4. The equibiaxial tensile test fixture for an elastic plate according to claim 1, characterized in that: The stretching assembly at least has a test bench, a cushion block is arranged in the middle of the test bench, the clamping assembly is installed at the periphery of the cushion block, a winding bracket is arranged on the test bench outside the cushion block, the winding bracket is arranged corresponding to the clamping assembly, and the winding is wound on the winding bracket.

5. The equibiaxial tensile test fixture for elastic plates according to claim 4, characterized in that: The winding bracket has at least a base, which is an inverted π-shaped structure, with a horizontal base and two vertical side panels. The winding bracket is fixed to the test bench through the base, and a rotatable winding wheel is supported between the two side panels by a screw, and the winding wire is wound on the winding wheel.

6. The equibiaxial tensile test fixture for elastic plates according to claim 5, characterized in that: The transmission assembly has at least a movable plate, which is located below the test bench and has a center hole. The transmission screw passes through the movable plate and extends upward to the center of the test bench to ensure the center coaxiality of the movable plate when the transmission screw moves up and down. A high-precision force sensor is also provided at the connection between the transmission screw and the movable plate to detect the total force value transmitted to the movable plate by the clamping assembly. A fixing piece is provided outside the center hole of the movable plate, and the second end of the winding is connected to the fixing piece.

7. The equibiaxial tensile test fixture for an elastic plate according to claim 6, characterized in that: The fixing member is arranged corresponding to the winding bracket and the clamping assembly.

8. The equibiaxial tensile test fixture for an elastic plate according to claim 6, characterized in that: The movable plate also has a guide hole, a guide column is passed through the guide hole, two ends of the guide column are respectively connected to the test bench and the test machine, and are arranged parallel to the transmission screw.

9. A testing machine, characterized in that: The testing machine has a testing host, which has a shell. The equibiaxial tensile test fixture for an elastic plate described in any one of claims 1 to 8 is installed above the shell. The shell of the testing host has a motor, which is connected to the bottom end of the transmission screw of the equibiaxial tensile test fixture for an elastic plate described in any one of claims 1 to 8, and drives the transmission screw to drive the movable plate to move up and down.

10. The testing machine according to claim 9, characterized in that: A bracket is vertically arranged above the shell of the test host, an extensometer frame is arranged on the bracket, a video extensometer is installed on the extensometer frame, and a lens of the video extensometer is located directly above the sample to be tested. The video extensometer is a non-contact extensometer, which is used to observe and record the change of the middle gauge length of the sample to be tested, and obtain the data change curve of the elastomeric material during the stretching process through software, and calculate the various performance parameters of the elastomeric material under the equibiaxial tensile strain state.

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