A superconducting cable bending test device

Abstract

The application relates to the technical field of superconducting cable bending test, and particularly discloses a superconducting cable bending test device, which comprises a table plate with a first through hole, a second through hole and a third through hole, the first through hole is square and is provided with a plurality of first through holes; a limiting plate is arranged on the surface of the table plate, the upper part of the limiting plate is provided with a plurality of fourth through holes, the fourth through holes are arranged above the first through holes, the lower part of the limiting plate is provided with an arc-shaped notch, the side wall of the notch forms a first fitting surface; a disc is arranged on the surface of the table plate, the middle part of the disc is provided with a fifth through hole, the fifth through hole is arranged on the second through hole, the outer edge of the disc is provided with a second fitting surface; a first bolt is used for fixing the limiting plate on the table plate through the fourth through hole and the first through hole; and a second bolt is used for fixing the disc on the table plate through the fifth through hole and the second through hole. The superconducting cable bending test device is used for uniformly bearing the force of the superconducting cable in the bending process, avoids damaging the superconducting cable, and improves the test accuracy.

Description

Technical Field

[0001] This invention relates to the field of superconducting cable bending testing technology, and in particular to a superconducting cable bending testing device. Background Technology

[0002] Most superconducting cable bending test equipment uses a binding method to fix the superconducting cable to an arc-shaped groove or wall, which easily leads to the following problems: 1. When bending and fixing the superconducting cable, the binding straps or fixing tools used can cause stress concentration, which may damage the outer tape of the superconducting cable, affecting its performance and test accuracy. 2. During testing, as the bending radius decreases, the rebound force of the superconducting cable increases, and the cable may fail to adhere properly to the groove or wall at both ends or in the middle, resulting in inaccurate test data and the inability to obtain true bending performance data. Therefore, the technical solution of this application is urgently needed to solve the above problems. Summary of the Invention

[0003] The purpose of this invention is to provide a superconducting cable bending test device that ensures uniform stress on the superconducting cable during bending, avoids damage to the superconducting cable, and improves the accuracy of the test.

[0004] To achieve the above objectives, the present invention provides a superconducting cable bending test device, comprising:

[0005] A platform has a first through hole, a second through hole and a third through hole. The first through hole is square and has multiple holes. The first through hole extends from the upper part of the platform to the lower part of the platform. The third through hole has multiple holes and is located at the lower part of the platform. The second through hole is located between the first through hole and the third through hole.

[0006] A limiting plate is provided on the surface of the platform. The upper part of the limiting plate has a plurality of fourth through holes, which are located above the first through holes. The lower part of the limiting plate has an arc-shaped notch, and the sidewall of the notch forms a first mating surface.

[0007] A disc is disposed on the surface of the platform. The disc has a fifth through hole in the middle, which is disposed on the second through hole. The outer edge of the disc has a second mating surface. At least half of the second mating surface is spaced apart in the notch. The superconducting cable is clamped between the first mating surface and the second mating surface.

[0008] A first bolt, passing through the fourth through hole and the first through hole, fixes the limiting plate to the platform; and

[0009] The second bolt passes through the fifth through hole and the second through hole to fix the disk to the platform.

[0010] In some embodiments, the first mating surface is a curved surface recessed into the limiting plate, and the second mating surface is a curved surface recessed into the disk.

[0011] In some embodiments, the disk includes an outer ring and a plurality of pillars integrally formed with the outer ring, the first end of each pillar is connected to the inner wall of the outer ring, the second ends of each pillar are interconnected, and the fifth through hole is provided on the second end of the pillar.

[0012] In some embodiments, the thickness of the outer ring is equal to the thickness of the support column, and the surface of the outer ring is flush with the surface of the support column.

[0013] In some embodiments, if the maximum width of the notch is a, the outer diameter of the disk is b, and the diameter of the superconducting cable is c, then a = b + 2c.

[0014] In some embodiments, when the superconducting cable is clamped between the first mating surface and the second mating surface, the connectors at both ends of the superconducting cable extend out of the notch and are located on the third through hole, and the connectors of the superconducting cable are fixed on the platform by passing a binding rope through the third through hole.

[0015] In some embodiments, the platform, the limiting plate, and the disc are all made of epoxy resin material.

[0016] In some embodiments, the thickness of the limiting plate is equal to the thickness of the disk, and the surface of the limiting plate is flush with the surface of the disk.

[0017] In some embodiments, the first bolt slides along the first through hole to adjust the distance between the limiting plate and the disk.

[0018] In some embodiments, the first through holes are arranged in parallel, and the plurality of third through holes are distributed in a rectangular array.

[0019] This invention provides a superconducting cable bending test device, which has the following advantages compared with the prior art:

[0020] The lower part of the limiting plate has an arc-shaped notch, the sidewall of the notch forms a first contact surface, and the outer edge of the disc has a second contact surface. At least half of the second contact surface is spaced apart in the notch. The superconducting cable is clamped between the first contact surface and the second contact surface, so that the superconducting cable is subjected to uniform force during bending, avoiding damage to the superconducting cable and improving the accuracy of the test. Attached Figure Description

[0021] Figure 1This is a three-dimensional structural schematic diagram of a superconducting cable bending test device provided in some embodiments of the present invention.

[0022] Figure 2 This is a three-dimensional structural diagram of the platform of the superconducting cable bending test device provided in some embodiments of the present invention.

[0023] Figure 3 This is a three-dimensional structural diagram of the limiting plate and disk of the superconducting cable bending test device provided in some embodiments of the present invention.

[0024] Figure 4 This is a partially enlarged structural diagram of the limiting plate of the superconducting cable bending test device provided in some embodiments of the present invention.

[0025] In the picture:

[0026] 1. Platform; 11. First through hole; 12. Second through hole; 13. Third through hole;

[0027] 2. Limiting plate; 21. Fourth through hole; 22. Notch; 23. First mating surface;

[0028] 3. Disc; 31. Fifth through hole; 32. Second mating surface; 33. Outer ring; 34. Support column;

[0029] 4. First bolt;

[0030] 5. Second bolt;

[0031] 6. Superconducting cables. Detailed Implementation

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0033] It should be understood that in the description of this application, the terms "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. That is, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, unless otherwise stated, "a plurality of" means two or more.

[0034] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0035] The test apparatus in this application targets a CORC (Conductor on Round Core) cable, a high-performance superconducting conductor designed based on YBCO (yttrium barium copper oxide) tape, a second-generation high-temperature superconducting material. YBCO tape, as a representative of second-generation high-temperature superconducting materials, possesses numerous excellent physical and engineering properties, such as a high critical magnetic field, strong current-carrying capacity, and good mechanical properties. These characteristics make YBCO tape an ideal choice for nuclear fusion devices, particle accelerators, high-field magnets, and other high-energy physics experimental equipment. Especially in high-field magnet applications, YBCO tape can maintain stable superconducting performance under extremely low temperatures and strong magnetic fields, which is crucial for achieving efficient and compact magnet designs.

[0036] CORC cables are compact and flexible superconducting conductors. Their core design concept involves winding multiple YBCO tapes at specific helical angles around a circular core. This design not only fully utilizes the high critical current characteristics of YBCO tapes but also significantly reduces AC losses through optimized tape arrangement. Furthermore, the flexible design of CORC cables allows them to adapt to complex geometries and mechanical environments. For example, when wound into coils or stranded into multi-stage cables, it effectively reduces the impact of mechanical stress on superconducting performance. Compared to traditional superconducting cable structures, CORC cables offer several significant advantages:

[0037] Low AC loss: Due to the spiral winding of YBCO tape, the eddy current loss of CORC cable under alternating magnetic field is significantly reduced, which gives it a clear advantage in high-frequency or dynamic magnetic field applications.

[0038] High critical current: CORC cables, through the parallel structure of multiple YBCO tapes, can carry higher total current while maintaining a high current density.

[0039] Compact structure: The circular core design and flexible structure of CORC cables make them highly adaptable to space-constrained applications, such as the complex magnet systems of nuclear fusion devices.

[0040] Easy to cabling: The modular design of CORC cables makes them easy to combine with other cables or structures to form multi-level cables or complex coils, thereby meeting different engineering needs.

[0041] However, despite the numerous advantages of CORC cables, they still face some challenges in practical applications. For example, during the winding into coils or stranding into multi-stage cables, the cables are subjected to complex mechanical stresses, especially bending stress. This stress can cause changes in the microstructure of the YBCO tape, thereby affecting its superconducting properties. Therefore, studying the critical current variation law of CORC cables under bending stress is of great significance for optimizing their design and process parameters.

[0042] To accurately evaluate the performance of CORC cables under bending stress, the testing equipment needs to be able to simulate the stress state of the cable in real-world applications. Specifically, the testing equipment should have the following functions:

[0043] Precise control of bending stress: A controllable bending load is applied through a mechanical structure to simulate the stress conditions of a cable during winding or stranding.

[0044] Protect the integrity of the strip: Avoid mechanical damage to the YBCO strip caused by the testing equipment and ensure the accuracy of the test results.

[0045] Real-time monitoring of critical current: While applying bending stress, the change in the cable's critical current is measured in real time to assess its performance degradation.

[0046] By designing efficient testing equipment, it is possible to gain a deeper understanding of the performance of CORC cables under complex mechanical environments, thereby providing a scientific basis for their engineering applications in nuclear fusion, high-energy physics, and other high-field applications. This will not only help promote the further development of CORC cable technology but also open up new possibilities for the application of superconducting materials in more fields.

[0047] CORC cables, as a novel type of high-temperature superconducting cable, have broad application prospects in power transmission, magnetic coils, and other fields. However, in practical applications, CORC cables, when composited into multi-stage cables or wound into coils, face complex mechanical environments, especially when operating at low temperatures. The cables must withstand not only the stress caused by low-temperature contraction but also enormous electromagnetic loads. These conditions make the mechanical properties of CORC cables one of the key factors affecting their engineering applications. Bending stress is one of the main mechanical stresses experienced by CORC cables during winding or stranding, directly affecting their critical current (i.e., the maximum current that the superconducting material can carry under specific conditions). Therefore, studying the influence of bending stress on the critical current of CORC cables and optimizing the process parameters for winding coils or stranding multi-stage cables based on these principles is of great significance for improving the reliability and economy of their engineering applications.

[0048] To thoroughly investigate the performance of CORC cables under bending stress, researchers typically need to simulate the stress conditions the cables experience in real-world applications within a laboratory environment. Specifically, this involves applying a controlled bending load to cable samples while simultaneously measuring the critical current. However, testing directly on superconducting coils is not only costly but also complex and difficult to control precisely. Therefore, researchers usually use straight conductor structures as test samples to simulate the stress state of cables during winding or stranding. While this testing method simplifies experimental conditions, it still faces many challenges.

[0049] First, existing superconducting cable bending testing equipment has certain design limitations. For example, the testing equipment may cause mechanical damage to the superconducting tape on the outer layer of the CORC cable, especially under high stress conditions, which may lead to distorted test results. Second, because the contact surfaces between the superconducting cable and the testing equipment cannot be perfectly aligned, uneven stress distribution may occur, thus affecting the accuracy of the test data. These problems make it difficult for existing testing equipment to accurately reflect the bending performance of CORC cables in practical applications, limiting further research in this area.

[0050] To address these issues, designing an efficient and cost-effective testing device is crucial. This device needs to possess several key characteristics: First, it should be able to precisely control the bending stress applied to the cable sample to ensure the repeatability and comparability of test conditions; second, the device should avoid damaging the outer cable sheath to maintain sample integrity; and finally, the device should ensure good contact between the cable and the testing equipment to reduce the impact of uneven stress distribution on test results. By optimizing the design of the testing device, researchers can more accurately evaluate the critical current performance of CORC cables under bending stress, thus providing reliable data support for practical engineering applications.

[0051] Furthermore, with the continuous development of superconducting technology, the application scenarios of CORC cables are constantly expanding. For example, in nuclear fusion devices, high-energy physics experimental equipment, and large-scale power transmission systems, the performance of CORC cables directly affects the operating efficiency and safety of the entire system. Therefore, in-depth research on the performance of CORC cables under complex mechanical environments not only helps improve the reliability of their engineering applications but also provides a theoretical basis for further optimization of superconducting materials.

[0052] In summary, the bending stress experienced by CORC cables during winding or stranding has a significant impact on their critical current performance. By designing efficient testing devices, researchers can more accurately simulate the stress state of cables in practical applications, thus providing a scientific basis for optimizing cable design and process parameters. This will not only help improve the engineering application value of CORC cables but also promote the widespread application of superconducting technology in more fields.

[0053] like Figures 1-4 As shown, the superconducting cable bending test device provided in this embodiment of the invention includes a platform 1, a limiting plate 2, a disc 3, a first bolt 4, and a second bolt 5. The limiting plate 2 is fixed to the platform 1 by the first bolt, and the disc 3 is fixed to the platform 1 by the second bolt 5.

[0054] The platform 1 has a first through hole 11, a second through hole 12, and a third through hole 13. The first through hole 11 is square and has multiple holes, extending from the upper part of the platform 1 to the lower part. The third through hole 13 has multiple holes and is located at the lower part of the platform 1. The second through hole 12 is located between the first through hole 11 and the third through hole 13. Thus, the first through hole 11 is used to install the limiting plate 2 and facilitates the position adjustment of the positioning plate 2 to accommodate the clamping of superconducting cables 6 of different diameters; the second through hole 12 is used for the positioning and installation of the disc 3; and the third through hole 13 is used to fix both ends of the superconducting cable 6.

[0055] A limiting plate 2 is disposed on the surface of the platform 1. The upper part of the limiting plate 2 has multiple fourth through holes 21, which are located above the first through hole 11. The lower part of the limiting plate 2 has an arc-shaped notch 22, and the sidewall of the notch 22 forms a first mating surface 23. The fourth through holes 21 are used for mounting the limiting plate 2, and the notch 22 can cooperate with the disc 3 to clamp the superconducting cable 6, causing the superconducting cable 6 to bend.

[0056] A disc 3 is disposed on the surface of the platform 1. The disc 3 has a fifth through hole 31 in its center, which is located above the second through hole 12. The outer edge of the disc 3 has a second mating surface 32, with at least half of the second mating surface 32 spaced apart in the notch 22. The superconducting cable 6 is clamped between the first mating surface 23 and the second mating surface 32. The fifth through hole 31 is used for mounting the disc 3. The first mating surface 23 and the second mating surface 32 cooperate to clamp the superconducting cable 6, ensuring uniform stress on the superconducting cable 6 during bending, preventing damage to the superconducting cable 6, and improving the accuracy of the test.

[0057] The first bolt 4 passes through the fourth through hole 21 and the first through hole 11 to fix the limiting plate 2 onto the platform 1. Specifically, tightening the first bolt 4 with a nut will fix the limiting plate 2 onto the platform 1, and loosening the first bolt 4 with a nut will allow the limiting plate 2 to move along the extension direction of the first through hole 11 to adjust the distance between the limiting plate 2 and the disc 3.

[0058] The second bolt 5 passes through the fifth through hole 31 and the second through hole 12 to fix the disc 3 onto the platform 1.

[0059] Based on the above structural configuration, the structural design of the limiting plate 2 and the disc 3 is crucial. They work together to ensure that the superconducting cable 6 is subjected to uniform stress during the bending test, thereby preventing damage to the superconducting cable 6 and improving the accuracy of the test. Specifically, the lower part of the limiting plate 2 is designed with an arc-shaped notch 22, the sidewall of which forms a first contact surface 23. At the same time, the outer edge of the disc 3 is designed with a second contact surface 32, and at least half of the second contact surface 32 is spaced out in the notch 22 of the limiting plate 2. This design allows the superconducting cable 6 to be tightly clamped between the first contact surface 23 and the second contact surface 32, thereby achieving a uniform stress distribution during bending. This ensures that the superconducting cable 6 maintains close contact with the first contact surface 23 and the second contact surface 32 throughout the bending process, thus preventing the superconducting cable 6 from slipping or shifting during the test.

[0060] like Figure 4 As shown, in some embodiments, the first contact surface 23 is a curved surface recessed towards the limiting plate 2, and the second contact surface 32 is a curved surface recessed towards the disk 3. This increases the contact area between the first contact surface 23 and the second contact surface 32 and the superconducting cable 6, thereby avoiding stress concentration.

[0061] like Figure 3 As shown, in some embodiments, the disk 3 includes an outer ring 33 and multiple supports 34 integrally formed with the outer ring 33. The first end of each support 34 is connected to the inner wall of the outer ring 33, and the second ends of each support 34 are interconnected. A fifth through hole 31 is provided on the second end of the support 34. The structure of the disk 3 can reduce weight and save material usage.

[0062] In some embodiments, the thickness of the outer ring 33 is equal to the thickness of the support column 34, and the surface of the outer ring 33 is flush with the surface of the support column 34. This maintains the flatness of the disc 3's shape, facilitating its installation and use.

[0063] In some embodiments, the maximum width of the notch 22 is a, the outer diameter of the disk 3 is b, and the diameter of the superconducting cable 6 is c, then a = b + 2c. This ensures that the superconducting cable 6 is subjected to balanced forces at the contact points with the first contact surface 23 and the second contact surface 32.

[0064] like Figure 1As shown. In some embodiments, when the superconducting cable 6 is clamped to the first mating surface 23 and the second mating surface 32, the connectors at both ends of the superconducting cable 6 extend into notches located on the third through hole 13. A binding rope is then passed through the third through hole 13 to secure the connectors of the superconducting cable 6 to the platform 1. This prevents damage to the superconducting cable 6 due to movement of the connectors during the assembly of the bending test device or the connection of the test circuit.

[0065] In some embodiments, the platform 1, the limiting plate 2, and the disc 3 are all made of epoxy resin. This offers the following advantages:

[0066] Low-temperature adaptability: Testing of superconducting cables typically requires cryogenic environments, and epoxy resin maintains good mechanical properties and dimensional stability at low temperatures, making it an ideal material for testing equipment. Reduced cable damage: The smooth surface and moderate hardness of epoxy resin prevent mechanical damage to the outer tape when clamping the superconducting cable. This is particularly important for protecting the brittle YBCO tape. Lightweight design: Compared to metal materials, epoxy resin has a lower density, reducing the overall weight of the testing equipment and facilitating experimental operation and equipment movement.

[0067] In some embodiments, the thickness of the limiting plate 2 is equal to the thickness of the disk 3, and the surface of the limiting plate 2 is flush with the surface of the disk 3. This ensures that the limiting plate 2 and the disk 3 can be neatly mounted on the platform 1. This accommodates the testing requirements of superconducting cables 6 of different diameters.

[0068] like Figure 1 and 2 As shown, in some embodiments, the first bolt 4 slides along the first through hole 11 to adjust the distance between the limiting plate 2 and the disk 3. The position of the limiting plate 2 can be fixed by tightening the first bolt 4.

[0069] like Figure 2 As shown, in some embodiments, the first through holes 11 are arranged in parallel, and the multiple third through holes 13 are distributed in a rectangular array. By installing multiple first bolts 4 in the first through holes 11, the stability of the mounting structure of the limiting plate 2 can be improved; the multiple third through holes 13 are more conducive to the fixing of the joints of the superconducting cable 6.

[0070] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A superconducting cable bend test apparatus, characterized by, The utility model relates to a superconducting cable fixing device, comprising: a platform having a plurality of first through holes, a plurality of second through holes and a plurality of third through holes, the first through holes being square and extending from the upper part of the platform to the lower part of the platform, the third through holes being located at the lower part of the platform, and the second through holes being located between the first through holes and the third through holes; a limiting plate arranged on the surface of the platform, the upper part of the limiting plate having a plurality of fourth through holes arranged above the first through holes, and the lower part of the limiting plate having a plurality of notches in the shape of an arc, the side walls of the notches forming a first fitting surface; a disc arranged on the surface of the platform, the middle part of the disc having a fifth through hole arranged above the second through hole, and the outer edge of the disc having a second fitting surface, at least half of the second fitting surface being arranged in the notches, and the superconducting cable being clamped between the first fitting surface and the second fitting surface; a first bolt penetrating the fourth through holes and the first through holes to fix the limiting plate on the platform; and a second bolt penetrating the fifth through hole and the second through hole to fix the disc on the platform. The first fitting surface is a curved surface recessed towards the limiting plate, and the second fitting surface is a curved surface recessed towards the disc.

2. The superconducting cable bend test apparatus of claim 1, wherein, The disc comprises an outer ring and a plurality of support rods integrally formed with the outer ring, the first ends of the support rods being connected to the inner wall of the outer ring, and the second ends of the support rods being connected to each other, and the fifth through hole being arranged on the second ends of the support rods.

3. The superconducting cable bend test apparatus of claim 1, wherein, The thickness of the outer ring is equal to the thickness of the support rods, and the surface of the outer ring is flush with the surface of the support rods.

4. The superconducting cable bend test apparatus of claim 3, wherein, The maximum width of the notches is a, the outer diameter of the disc is b, and the diameter of the superconducting cable is c, and a=b+2c is satisfied.

5. The superconducting cable bend test apparatus of claim 1, wherein, When the superconducting cable is clamped between the first fitting surface and the second fitting surface, the connectors at both ends of the superconducting cable extend out of the notches and are located on the third through holes, and the connectors of the superconducting cable are fixed on the platform by a binding rope penetrating the third through holes.

6. The superconducting cable bend test apparatus of claim 1, wherein, The platform, the limiting plate and the disc are all made of epoxy resin material.

7. The superconducting cable bend test apparatus of claim 1, wherein, The thickness of the limiting plate is equal to the thickness of the disc, and the surface of the limiting plate is flush with the surface of the disc.

8. The superconducting cable bend test apparatus of claim 1, wherein, The first bolt slides along the first through holes to adjust the distance between the limiting plate and the disc.

9. The superconducting cable bend test apparatus of claim 1, wherein, The first through holes are arranged in parallel, and the third through holes are arranged in a rectangular array.

10. The superconducting cable bend test apparatus of claim 1, wherein, ​

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