A high-temperature superconducting tape critical current testing device and testing method

Abstract

The present invention provides a critical current test device and test method for high-temperature superconducting tapes, belonging to the technical field of high-temperature superconducting tape performance testing, including: a test bench, a connecting beam, a first pulling element, the first pulling element is fixedly connected to the middle of the connecting beam, and the two ends of the connecting beam are rotatably connected to the friction locking device; a friction locking fitting part, the friction locking fitting parts are provided with two, and the two friction locking fitting parts are respectively adapted to the friction locking devices on both sides of the test bench; a second pulling element, the second pulling element is arranged opposite to the first pulling element, and the second pulling element is fixedly connected to the two friction locking fitting parts. By designing the configuration of the test device, the size structure is reduced, which makes it easier to place the test device under an extremely high magnetic field, and solves the problem of uneven force after the size structure is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature superconducting tape performance testing, and in particular relates to a high-temperature superconducting tape critical current testing device and a testing method. Background Art

[0002] High-temperature superconducting tapes are widely used in large scientific facilities such as high-field magnets, fusion reactors, and particle accelerators due to their excellent electrical properties, such as extremely low resistance and high critical current density. However, in practical applications, these superconducting tapes often need to withstand complex working environments, including extremely low temperatures, extremely high magnetic fields, and mechanical stress. The complex multi-field coupling effect between temperature fields, magnetic fields, and mechanical stresses causes the critical current of high-temperature superconducting tapes to exhibit nonlinear degradation. This coupling effect is more significant in confined spaces because space limitations exacerbate the difficulty of temperature control and the unevenness of stress distribution.

[0003] In the prior art, the devices for testing the mechanical properties of high-temperature superconducting tapes are mainly concentrated in self-field or DC magnets with large room temperature holes, and less consideration is given to stress loading and measurement in a small space. Traditional superconducting tape critical current measurement devices usually cannot meet the requirements of precise stress loading in a small space, especially when performing service tests of high-temperature superconducting tapes in high-field magnets with extremely small room temperature holes, conventional equipment is difficult to use. Therefore, the development of a device that can accurately apply mechanical stress in a small space is crucial for the performance evaluation and optimization of superconducting tapes. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a high-temperature superconducting tape critical current test device and test method, the test device is used to measure the critical current of the high-temperature superconducting tape under different tensile and compressive loads and extremely high magnetic fields. The present invention reduces the size structure through the configuration design of the test device, which is convenient for placing the test device under extremely high magnetic fields, such as in a pulse magnet with extremely small aperture at room temperature, and a small space with a maximum diameter of 32mm, and solves the problem of uneven force after reducing the size structure.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a critical current testing device for a high-temperature superconducting tape, which is used to measure the critical current of a high-temperature superconducting tape under extremely low temperatures, different tensile and compressive loads and extremely high magnetic fields, and comprises: a test bench, wherein the test bench has a test surface, wherein the thickness of the test surface area is the same, wherein two ends of the test bench are bent toward the same side to form a bent portion, and the side surfaces of the two ends of the test bench are fixedly connected with a friction locking device; a connecting beam, wherein the connecting beam is arranged in a cavity formed by the two bent portions; a first pulling element, wherein the first pulling element is fixedly connected to the middle portion of the connecting beam, and the two ends of the connecting beam are rotatably connected to the friction locking device; a friction locking fitting portion, wherein two friction locking fitting portions are provided, and the two friction locking fitting portions are respectively adapted to the friction locking devices on both sides of the test bench; and a second pulling element, wherein the second pulling element is arranged opposite to the first pulling element, and the second pulling element is fixedly connected to the two friction locking fitting portions.

[0007] Furthermore, the friction locking device has a tooth portion and a fixed portion, the outer contour of the tooth portion is a circle with the rotation center as the center, and the fixed portion is fixedly connected to the test bench; the friction locking matching portion is a rack, and the tooth portion meshes with the rack.

[0008] Furthermore, the distance between the rotation center and the axis of the first pulling element or the axis of the second pulling element is smaller than the distance between the connection position of the friction locking device and the test bench and the axis of the first pulling element or the axis of the second pulling element.

[0009] Furthermore, in the cross-section of the test bench, the thickness of the bending portion is greater than the thickness of the test surface area, the test surface area is connected to the bending portion through an arc line, a first arc line is formed on the inner side, and a second arc line is formed on the outer side; the test bench and the friction locking device are fixedly connected by at least two fastening devices; one fastening device is close to one side of the test surface area and is located between the line connecting the connection points of the test surface area and the arc line and the line connecting the midpoints of the two arc lines; the other fastening device is located away from the test surface area and is arranged in the bending portion area.

[0010] Furthermore, when the first pulling element and the second pulling element do not apply external force, the center of the first arc line coincides with the rotation center of the friction locking device, and the fastening device is located on the same arc radius with the rotation center as the center;

[0011] The distance R3 between the fastening device and the rotation center and the first arc radius R1 satisfy the following formula:

[0012] ;

[0013] Where H0 is the thickness of the test surface area, is a correction coefficient, and its value range is 0.2-0.4; the diameter of the fastening device is not greater than 0.2H0.

[0014] Furthermore, when the first pulling element and the second pulling element do not apply external force, the fastening device on the side away from the test surface area is located on the line connecting the rotation centers of the two ends of the connecting beam.

[0015] Furthermore, a line connecting the two ends of the fastening device and a line connecting the rotation centers of the two ends of the connecting beam have an angle α, 50°≤α≤70°.

[0016] Furthermore, the thickness of the connecting beam is the same as the thickness of the test surface area, and the width of the connecting beam is 2 / 5-3 / 5 of the width of the test surface.

[0017] Furthermore, the length of the test surface area is 17-20 mm, and the width is 8-12 mm.

[0018] The present invention also provides a testing method for the above-mentioned testing device, comprising the following steps: welding a high-temperature superconducting tape to the middle position of the test surface area, and pasting a strain gauge at the center position of the high-temperature superconducting tape, and connecting current leads on both sides of the high-temperature superconducting tape; placing the test surface in a preset temperature environment and the center position of the magnetic field; applying tensile stress or compressive stress to the tape through a first pulling element and a second pulling element, recording and analyzing temperature, strain and magnetic field strength data information.

[0019] The beneficial effects brought by the technical solution provided by the embodiment of the present invention include:

[0020] (1) The detection device provided by the present invention has fewer structural components. A high-temperature superconducting tape is welded to the middle of the test surface, and a strain gauge is welded on the surface of the high-temperature superconducting tape. Pressure or tension is applied to the tape by a first pulling element and a second pulling element, thereby measuring the critical current density of the tape producing different strains under a preset temperature and magnetic field. Since the structural features in the present application are few, it is suitable for placement in extremely high magnetic fields, such as a pulse magnet with an extremely small aperture at room temperature, and a small space with a maximum diameter of 32 mm, and solves the problem of uneven force after reducing the size of the structure.

[0021] (2) The detection process needs to achieve a preset measurement accuracy. For example, during compression or tension, the deformation of the high-temperature superconducting tape needs to meet the granularity requirements of the measured deformation amount and the consistency of deformation during the deformation process. The prior art requires that the strain gauge be pasted in the maximum uniform strain area. If the area where the maximum strain of the high-temperature superconducting tape occurs during deformation is not within the area where the strain gauge is pasted, there will be a problem of incorrect correspondence between the strain and the critical current. The present application achieves accurate measurement while reducing the probability of component damage by using fewer structural components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A three-dimensional schematic diagram of a testing device provided in an embodiment of the present invention;

[0024] Figure 2 A three-dimensional schematic diagram of a testing device provided by an embodiment of the present invention from another perspective;

[0025] Figure 3 A front view of a testing device provided by an embodiment of the present invention;

[0026] Figure 4 A front view of a test bench provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of a force arm of a test device provided in an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of the forces acting on the connecting beam and the first pulling element provided by an embodiment of the present invention;

[0029] Figure 7 A partial side sectional view of a testing device provided in an embodiment of the present invention.

[0030] Explanation of the accompanying drawings: 1. test bench; 10. test surface; 100. first circular arc line; 101. second circular arc line; 11. bending portion; 12. friction locking device; 120. tooth portion; 121. fixing portion; 122. fastening device; 2. connecting beam; 20. shaft; 31. first pulling element; 32. second pulling element; 4. friction locking fitting portion. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Example 1

[0037] The embodiment of the present invention discloses a critical current testing device for a high temperature superconducting tape, wherein the testing device is used to measure the critical current of a high temperature superconducting tape under different tensile and compressive loads and extremely high magnetic fields, such as Figure 1 and 2As shown, it includes: a test bench 1, the test bench has a test surface 10, the test surface 10 has the same thickness in the area, the two ends of the test bench 1 are bent to the same side to form a bending portion 11, and the two end sides of the test bench 1 are fixedly connected with a friction locking device 12; a connecting beam 2, the connecting beam 2 is arranged in a cavity formed by the two bending portions 11; a first pulling element 31, the first pulling element 31 is fixedly connected to the middle part of the connecting beam 2, and the two ends of the connecting beam 2 are rotatably connected to the friction locking device 12; a friction locking fitting portion 4, two friction locking fitting portions 4 are provided, and the two friction locking fitting portions 4 are respectively adapted to the friction locking devices 12 on both sides of the test bench 1; a second pulling element 32, the second pulling element 32 is arranged opposite to the first pulling element 31, and the second pulling element 32 is fixedly connected to the two friction locking fitting portions 4.

[0038] The detection device provided by the present invention has fewer structural components, a high-temperature superconducting tape is welded to the middle of the test surface 10, and a strain gauge is welded on the surface of the high-temperature superconducting tape, and pressure or tension is applied to the tape by a first pulling element and a second pulling element, thereby measuring the critical current density of different strains under a preset temperature and magnetic field; due to the few structural features in the present application, it is suitable for being placed in an extremely high magnetic field, such as a pulse magnet with a very small aperture at room temperature, and a small space with a maximum diameter of 32 mm, and solves the problem of uneven force after the size structure is reduced; secondly, the detection process needs to achieve a preset measurement accuracy, such as during the pressure or stretching process, the deformation of the high-temperature superconducting tape needs to meet the granularity requirements of the measured deformation amount, as well as the consistency of the deformation during the deformation process. The prior art requires that the strain gauge be pasted in the maximum uniform strain area. If the area where the maximum strain of the high-temperature superconducting tape occurs during deformation is not within the area where the strain gauge is pasted, the problem of incorrect correspondence between the strain and the critical current occurs, and the present application achieves accurate measurement while reducing the probability of component damage through fewer structural components.

[0039] It should be noted that the two ends of the connecting beam 2 in the embodiment of the present invention are rotatably connected to the friction locking device 12. Specifically, Figure 1 The connecting beam 2 is rotatably connected to the friction locking device 12 via the shaft 20, and the connection forms include: (1) the shaft 20 is fixedly connected to the connecting beam 2, and the shaft 20 is rotatably connected to the friction locking device 12; (2) the shaft 20 is rotatably connected to the connecting beam 2, and the shaft 20 is fixedly connected to the friction locking device 12; (3) the shaft 20 is rotatably connected to the connecting beam 2, and the shaft 20 is rotatably connected to the friction locking device 12. As long as the friction locking device and the connecting beam can be relatively rotatably connected, it will be sufficient.

[0040] like Figure 1 and 2In the present application, there are four friction locking devices 12, one group is symmetrically arranged on both sides of the test surface 10, each group includes two friction locking devices 12, the two friction locking devices 12 in each group are connected by the same axis 20, and the axes in each group are parallel to each other; there are two friction locking fitting parts 4, and the two are parallel to each other, each friction locking fitting part 4 is adapted to the friction locking devices at both ends of the same side of the test bench, that is, the friction locking fitting part 4 cooperates with the friction locking device to avoid large slippage between the two. Preferably, as Figure 1 In the embodiment, the friction locking device 12 has a toothed portion 120 and a fixed portion 121, the outer contour of the toothed portion is a circle with the rotation center as the center, the fixed portion 121 is fixedly connected to the test bench 1, and the friction locking mating portion 4 is a rack, and the toothed portion 120 is meshed with the rack. The rack meshes with the toothed portion to prevent the pressure or tension applied during the experiment from being greater than the preset pressure or tension of the test device, resulting in slippage between the two and interruption of the detection process.

[0041] Specifically, Figure 3 As shown, the distance L1 between the rotation center O and the axis of the first pulling element 31 or the axis of the second pulling element 32 is less than the distance L2 between the connection position of the friction locking device 12 and the test bench 1 and the axis of the first pulling element 31 or the axis of the second pulling element 32. Since the measuring device provided by the embodiment of the present invention is small in size to be implemented in a narrow space with a maximum diameter of 32 mm, L1 is set to be smaller than L2 to achieve maximum strength stability in limited structural features; secondly, L1 is set to be smaller than L2. At this time, the length left for the test surface 10 is increased, which is conducive to improving the uniformity and stability of the deformation of the middle part of the test surface 10. If L1 is set to be larger than L2, the same strain is achieved in the shorter test surface 10, and the non-uniformity of the stress distribution of the test surface 10 is greatly increased. The preferred L1 is (0.7-0.8) L2.

[0042] Specifically, Figure 1 and 4As shown, in the cross-section of the test bench 1, the thickness H1 of the bending portion 11 is greater than the thickness H0 of the test surface 10 area, and the test surface 10 area is connected to the bending portion 11 through an arc line, with a first arc line 100 formed on the inner side and a second arc line 101 formed on the outer side; the test bench 1 and the friction locking device 12 are fixedly connected by at least two fastening devices 122; one fastening device 122 is close to one side of the test surface 10 area and is located between the line X1 connecting the connection points of the test surface area and the arc line and the line X2 connecting the midpoints of the two arc lines; the other fastening device 122 is located away from the test surface area and is arranged in the bending portion 11 area. Through the above-mentioned arrangement, the strain generated under the action of external stress is mainly concentrated on the test surface 10 rather than in the bending portion 11 area. It should be noted that if the bending portion 11 area is deformed, since the test surface 10 is connected to the bending portion 11 area, the deformation of the bending portion 11 will also affect the strain state of the test surface, thereby avoiding the deterioration of the uniformity of the strain distribution of the test surface 10 and affecting the accuracy of subsequent measurement results. Preferably, H1 is not less than 1.1H0 and not greater than 1.6H0.

[0043] It should be noted that the fastening device 122 in the embodiment of the present invention is a pin, through which the friction locking device 12 is fixedly connected to the test bench; the number of the fastening devices 122 is at least two, and multiple fastening devices 122 may be provided. Figure 1 It can be seen from the figure that three fastening devices are provided in the embodiment of the present invention.

[0044] Specifically, Figure 3 As shown, when the first pulling element 31 and the second pulling element 32 do not apply external force, the center of the first arc line 100 coincides with the rotation center O of the friction locking device, and the fastening device 122 is located on the same arc radius with the rotation center O as the center; the distance R3 between the fastening device 122 and the rotation center O and the first arc radius R1 satisfy the following formula:

[0045] ;

[0046] Where H0 is the thickness of the test surface area, is a correction coefficient, and its value range is 0.2-0.4; the diameter of the fastening device 122 is not greater than 0.2H0. When the first pulling element 31 and the second pulling element 32 apply pressure or tension, no matter which fastening method is used, there is a problem of uneven stress distribution, and the thinner the thickness of the test surface 10 area, the higher the probability of unevenness. By limiting the setting method and setting position of the fastening device, the size of the test bench 1 can be reduced to the maximum extent possible while meeting the detection accuracy; ,and The value range of is 0.2-0.4, the connection position is close to the inner surface of the test bench, the size between the connection position and the outer surface of the test bench is large, the test bench body is supported by metal material, which has certain rigidity and deflection, and coordinates the stress unevenness to ensure that the test surface 10, especially the middle part, can have the maximum uniform strain; secondly, the diameter of the fastening device is limited to ensure that it will not affect the strength of the test bench.

[0047] Specifically, Figure 5 As shown, when the first pulling element 31 and the second pulling element 32 do not apply external force, the fastening device 122 on the side away from the test surface 10 area is located on the rotation center line X3 at both ends of the connecting beam 2. In the embodiment of the present invention, the friction locking device 12 is fixedly connected to the friction locking fitting part 4 by means of a tooth connection. At this time, there is a corresponding problem, that is, there is a certain probability that one or two of the four friction locking devices are in virtual connection with the friction locking fitting part, that is, the one or two friction locking devices in virtual connection cannot apply force. If the setting method is not appropriate at this time, there may be a problem of torsion of the test surface 10. Based on the above problem, in the embodiment of the present invention, the fastening device 122 on the side away from the test surface area is located on the rotation center line X3 at both ends of the connecting beam 2. At this time, the connecting beam 2 is subjected to force as follows: Figure 6 As shown, F1+F2=F0, at this time, the connecting beam 2 can be deformed under a smaller stress. Compared with the test surface 10, the connecting beam 2 is deformed first to coordinate the virtual connection problem between the friction locking device and the friction locking matching part. As the deformation of the connecting beam 2 gradually increases, the required stress increases, and the test surface 10 is also deformed. At this time, the uniformity of the deformation generated in the test surface 10 is greatly improved.

[0048] Specifically, Figure 5 As shown, the connecting line X4 between the two ends of the fastening device and the connecting line X3 between the rotation centers O at both ends of the connecting beam have an angle α, 50°≤α≤70°. The force arm of the deformation of the test surface 10 is parallel to the connecting line X4, and the force arm of the connecting beam 2 is parallel to the connecting line X3. When 50°≤α≤70°, it is more conducive to the deformation of the connecting beam 2 first to improve the deformation uniformity of the test surface.

[0049] Specifically, the thickness H2 of the connecting beam 2 is the same as the thickness H0 of the test surface 10. Figure 6 As shown, the width W1 of the connecting beam 2 is 2 / 5-3 / 5 of the width W2 of the test surface 10. The cross-sectional dimensions of the connecting beam 2 are limited to further ensure that the virtual connection dimension between the friction locking device and the friction locking matching portion is absorbed by the connecting beam 2.

[0050] Specifically, the length of the test surface area is 17-20 mm, and the width is 8-12 mm.

[0051] The test bench 1 in the present invention is made of copper alloy, preferably beryllium copper alloy; the friction locking device, the friction locking fitting part and the connecting beam are made of non-magnetic materials, such as non-magnetic stainless steel 304, and the first pulling element and the second pulling element are made of stainless steel.

[0052] Example 2

[0053] In the embodiment of the present invention, the test surface of the test bench 1 is 17.2 mm long, 10 mm wide, and 13 mm thick at the bending portion; the tooth diameter of the friction locking device is 8 mm, the outer diameter is 8.8 mm, the modulus is 0.4, the number of teeth is 20, and the thickness is 5 mm; the diameter of the fastening device is 1 mm, and the diameter of the shaft 20 is 2 mm. The above structure satisfies the measurement of the critical current density of high-temperature superconducting tape under different bending loads and extremely high magnetic fields in a space with a diameter of 32 mm.

[0054] Example 3

[0055] The embodiment of the present invention further provides a testing method for the above-mentioned testing device, comprising the following steps:

[0056] S1: welding a high-temperature superconducting tape to the middle of the test surface area, pasting a strain gauge at the center of the high-temperature superconducting tape, and connecting wires at both sides of the high-temperature superconducting tape.

[0057] The strip is welded to the beryllium copper alloy beam through high-performance solder wire S-Sn60A (melting point 145 degrees, to prevent the thermal performance of the high-temperature superconducting strip from decreasing). The rack is moved vertically upward by a tensile testing machine, so that the beryllium copper alloy beam is uniformly deformed, thereby generating a 0-0.4% deformation on the strip. For a 4mm wide REBCO high-temperature superconducting strip, the elastic modulus is about 157GPa. To produce a maximum deformation of 0.4% in the center of the superconducting layer of the strip, a tensile force of about 240N needs to be applied.

[0058] The maximum uniform strain is produced at a position about 5 mm in length in the center of the strip. During the test, the strip is placed in the center of the magnetic field, that is, the uniform area of ​​maximum tensile strain. A 5% error is allowed in the strain on both sides of the strip.

[0059] S2 places the detection device with the strain gauge attached in a preset temperature environment and at the center of the magnetic field.

[0060] S3 applies tensile stress or compressive stress to the first pulling element and the second pulling element, records temperature, strain and magnetic field strength data information and performs analysis.

[0061] By electrifying the magnet that generates the background magnetic field, the superconducting tape is placed in a specific magnetic field. Current is injected into the tape through the current lead, and the IV curve is measured. The voltage criterion for the test is 1μV / cm. When the voltage at both ends of the voltage lead reaches the voltage criterion, the corresponding current is the critical current of the tape under the stress.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-temperature superconducting tape critical current test device, the test device is used to measure the critical current of the high-temperature superconducting tape under different tensile and compressive loads and extremely high magnetic fields, characterized in that: include: A test bench, wherein the test bench has a test surface, the test surface area has the same thickness, the two ends of the test bench are bent to the same side to form a bending portion, and the two ends of the test bench are fixedly connected to the side surfaces with friction locking devices; the middle position of the test surface area is used for welding the high-temperature superconducting tape, and the strain gauge is pasted at the central position of the high-temperature superconducting tape; A connecting beam, the connecting beam being arranged in a cavity formed by the two bending portions; A first pulling element, wherein the first pulling element is fixedly connected to the middle portion of the connecting beam, and both ends of the connecting beam are rotatably connected to the friction locking device; A friction locking fitting part, wherein two friction locking fitting parts are provided, and the two friction locking fitting parts are respectively adapted to the friction locking devices on both sides of the test bench; a second pulling element, the second pulling element being arranged opposite to the first pulling element, and the second pulling element being fixedly connected to the two friction locking fitting parts; The friction locking device comprises a tooth portion and a fixing portion, the outer contour of the tooth portion is a circle with the rotation center as the center, and the fixing portion is fixedly connected to the test bench; The friction locking fitting portion is a rack, and the toothed portion is meshed with the rack.

2. The testing device according to claim 1, characterized in that: The distance between the rotation center and the first pulling element axis or the second pulling element axis is smaller than the distance between the connection point of the friction locking device to the test bench and the first pulling element axis or the second pulling element axis.

3. The testing device according to claim 2, characterized in that: In the cross section of the test bench, the thickness of the bending portion is greater than the thickness of the test surface area, the test surface area is connected to the bending portion through an arc line, a first arc line is formed on the inner side, and a second arc line is formed on the outer side; The test bench is fixedly connected to the friction locking device via at least two fastening devices; One fastening device is close to the test surface area and located between the line connecting the test surface area and the arc line connection point and the line connecting the midpoints of the two arc lines; the other fastening device is located away from the test surface area and is set in the bending area.

4. The testing device according to claim 3, characterized in that: When the first pulling element and the second pulling element do not apply external force, the center of the first arc line coincides with the rotation center of the friction locking device, and the fastening device is located on the same arc radius with the rotation center as the center; The distance R3 between the fastening device and the rotation center and the first arc radius R1 satisfy the following formula: R3-R1=λH0 ； Where H0 is the thickness of the test surface area, λ is the correction factor, and its value range is 0.2-0.4; The diameter of the fastening device is not greater than 0.2H0.

5. The testing device according to claim 4, characterized in that: When the first pulling element and the second pulling element do not apply external force, the fastening device on the side away from the test surface area is located on the line connecting the rotation centers of the two ends of the connecting beam.

6. The testing device according to claim 5, characterized in that: The connecting line between the two ends of the fastening device and the connecting line of the rotation centers at the two ends of the connecting beam have an angle α, 50°≤α≤70°.

7. The testing device according to claim 6, characterized in that: The thickness of the connecting beam is the same as that of the test surface area, and the width of the connecting beam is 2 / 5-3 / 5 of the width of the test surface.

8. The testing device according to claim 7, characterized in that: The test surface area has a length of 17-20 mm and a width of 8-12 mm.

9. A testing method based on the testing device according to any one of claims 1 to 8, characterized in that: The steps include: Welding a high-temperature superconducting tape to the middle of the test surface area, pasting a strain gauge at the center of the high-temperature superconducting tape, and connecting wires on both sides of the high-temperature superconducting tape; Place the test device with the strain gauge attached to it in a preset temperature environment and at the center of the magnetic field; Tensile stress or compressive stress is applied to the first pulling element and the second pulling element, and temperature, strain and magnetic field strength data information are recorded and analyzed.

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