Comprehensive stress calculation method and system for bitter plate of water-cooled magnet

Abstract

Disclosed is a comprehensive stress calculation method for Bitter plates of a water-cooled magnet, comprising: in finite element analysis software, using a plurality of three-dimensional slotted Bitter plates without a helix angle to construct a simplified coil model (S10); carrying out mesh generation on the coil model to obtain meshing nodes (S20); applying boundary conditions and loading conditions to the coil model after mesh generation, and then performing simulation, the boundary conditions comprising applying a corresponding node displacement coupling condition to slots of Bitter plates on the upper and lower end surfaces of the coil model and providing contact pairs on contact surfaces between all the Bitter plates, and the loading conditions comprising loading electromagnetic force to all the nodes of the coil model and applying axial force on the upper end surface of the coil model (S30); and, on the basis of a simulation result, calculating the stress distribution of the Bitter plates (S40). Further disclosed is a comprehensive stress calculation system for Bitter plates of a water-cooled magnet.

Description

Comprehensive stress calculation method and system for water-cooled magnet Bitter sheet

[0001] Related applications

[0002] This disclosure claims the benefit of priority to Chinese Patent Application No. 202311510763.6 filed on November 14, 2023 with the State Intellectual Property Office of China, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] The present disclosure relates to the technical field of water-cooled magnet simulation, and more specifically, to a method and system for calculating the comprehensive stress of a water-cooled magnet Bitter sheet. Background Art

[0004] Water-cooled magnets are an important component of steady-state strong magnetic field experimental facilities and the main experimental device of strong magnetic field laboratories. Due to their characteristics of high magnetic field intensity and fast field rise rate, water-cooled magnets have become a highly-regarded extreme conditions experimental platform. The current maximum magnetic field of water-cooled magnets can reach over 40T. Referring to Figures 1 to 4, the Bitter sheet 6 (as shown in Figure 1) and the insulating sheet 7 (as shown in Figure 2) are the two basic elements that make up the water-cooled magnet coil. The Bitter sheet 6 is provided with a plurality of Bitter sheet cooling water holes 3, and a radial slit 1 is provided. The outer edge of the Bitter sheet 6 has a plurality of Bitter sheet positioning holes 3. The insulating sheet 7 is provided with a plurality of insulating sheet cooling water holes 5, and the outer edge of the insulating sheet 7 has a plurality of insulating sheet positioning holes. According to the stacking method shown in Figure 3, the Bitter sheet 6 and the insulating sheet 7 are stacked in a specific regular staggered manner to form a spirally ascending current channel, thereby forming a water-cooled magnet coil (as shown in Figure 4).

[0005] Because Bitter inserts withstand significant electromagnetic forces, they are typically made of high-strength, high-conductivity copper alloys. Accurately calculating the stress distribution in Bitter inserts under electromagnetic forces is crucial for water-cooled magnet design. The paper "Design of the Resistive Insert for the Nijmegen 45 T Hybrid Magnet, IEEE Transactions on Applied Superconductivity, Vol. 30, No. 4, June 2020" proposes using a two-dimensional circularly symmetric model in ANSYS to calculate stress in Bitter inserts. However, this model only calculates stresses generated by electromagnetic forces along the radial direction and cannot account for the effects of axial electromagnetic pressure perpendicular to the plane of the Bitter insert and frictional forces between Bitter inserts on the stress distribution. Furthermore, this model ignores the presence of slits in the Bitter inserts and, consequently, their effect on the stress distribution. Consequently, this model results in significant stress errors and is unable to accurately calculate the true stress distribution in the Bitter inserts.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure is to solve the technical problem of how to obtain a more accurate stress distribution of a Bitter sheet while taking into account both the computational complexity and the convergence.

[0008] A first aspect of the present disclosure proposes a method for calculating the comprehensive stress of a Bitter sheet in a water-cooled magnet, the method comprising: constructing a simplified coil model in finite element analysis software using a plurality of three-dimensional Bitter sheets with slits and no helix angle; meshing the coil model to obtain mesh nodes; applying boundary conditions and load conditions to the meshed coil model and then performing simulation, wherein the boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end surfaces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, and the load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force to the upper end surface of the coil model; and calculating the stress distribution of the Bitter sheet based on the simulation results.

[0009] In the first aspect above, the method further includes: setting the friction coefficient between the conductor-insulating sheet contact pair as the insulation contact surface friction coefficient, and setting the friction coefficient of the conductor-conductor contact pair as the conductor contact surface friction coefficient.

[0010] In the above first aspect, the coil model includes a plurality of Bitter sheets arranged sequentially from bottom to top, and the slit angles of the Bitter sheets increase in the same direction.

[0011] In the first aspect mentioned above, the coil model includes Bitter sheets DISK1, DISK2, DISK3, DISK4 and DISK5 arranged in sequence from bottom to top, wherein the cutting angles of DISK1 and DISK5 are both 180 degrees, and the cutting angles of DISK2, DISK3 and DISK4 are 360-a degrees, 0 degrees and a degrees respectively, where a is the fan angle of the insulating sheet.

[0012] In the first aspect above, between the Bitter sheet DISK1 and the Bitter sheet DISK2, the contact pair with a contact angle of 360-2a to 360-a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to 360-2a and 360-a to 360 is a conductor-conductor contact pair; between the Bitter sheet DISK2 and the Bitter sheet DISK3, the contact pair with a contact angle of 360-a to 360 is a conductor-insulating sheet contact pair, and the contact angle of 0 to The contact pair with a contact angle of 360-a is a conductor-conductor contact pair; between the Bitter piece DISK3 and the Bitter piece DISK4, the contact pair with a contact angle of 0 to a is a conductor-insulating piece contact pair, and the contact pair with a contact angle of a to 360 is a conductor-conductor contact pair; between the Bitter piece DISK4 and the Bitter piece DISK5, the contact pair with a contact angle of a to 2a is a conductor-insulating piece contact pair, and the contact pairs with contact angles of 0 to a and 2a to 360 are conductor-conductor contact pairs.

[0013] In the first aspect, the Bitter sheets DISK2, DISK3 and DISK4 are all in a superposition state of radial expansion and slit cantilever beam movement.

[0014] In the above-mentioned first aspect, the corresponding node displacement coupling conditions are applied to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model, including: coupling the corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces of the coil model respectively; setting the axial displacements of all nodes on the Bitter sheet on the lower end surface to 0, and setting all displacements of the nodes with the largest node number on the Bitter sheet on the lower end surface to 0.

[0015] The second aspect of the present disclosure also proposes a comprehensive stress calculation system for water-cooled magnet Bitter sheets, which includes a model construction module, a model division module, a condition application module and a stress calculation module. The model construction module is used to construct a simplified coil model using multiple Bitter sheets with 3D slits and no helical angle in finite element analysis software. The model division module is used to mesh the coil model to obtain mesh division nodes, and the condition application module is used to apply boundary conditions and load conditions to the meshed coil model and then perform simulation. The boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end faces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, wherein the contact pairs include conductor-insulating sheet contact pairs and conductor-conductor contact pairs. The load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force to the upper end face of the coil model. The stress calculation module is used to calculate the stress distribution of the Bitter sheet based on the simulation results.

[0016] In the second aspect, the friction coefficient between the conductor-insulating sheet contact pair is set as the insulation contact surface friction coefficient, and the friction coefficient between the conductor-conductor contact pair is set as the conductor contact surface friction coefficient.

[0017] In the above second aspect, the coil model includes a plurality of Bitter sheets arranged sequentially from bottom to top, and the slit angles of the Bitter sheets increase in the same direction.

[0018] In the above-mentioned second aspect, the coil model includes Bitter sheets DISK1, DISK2, DISK3, DISK4 and DISK5 arranged in sequence from bottom to top, wherein the cutting angles of DISK1 and DISK5 are both 180 degrees, and the cutting angles of DISK2, DISK3 and DISK4 are 360-a degrees, 0 degrees and a degrees respectively, where a is the fan angle of the insulating sheet.

[0019] In the above second aspect, between the Bitter sheet DISK1 and the Bitter sheet DISK2, the contact pair with a contact angle of 360-2a to 360-a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to 360-2a and 360-a to 360 is a conductor-conductor contact pair; between the Bitter sheet DISK2 and the Bitter sheet DISK3, the contact pair with a contact angle of 360-a to 360 is a conductor-insulating sheet contact pair, and the contact angle of 0 to The contact pair with a contact angle of 360-a is a conductor-conductor contact pair; between the Bitter piece DISK3 and the Bitter piece DISK4, the contact pair with a contact angle of 0 to a is a conductor-insulating piece contact pair, and the contact pair with a contact angle of a to 360 is a conductor-conductor contact pair; between the Bitter piece DISK4 and the Bitter piece DISK5, the contact pair with a contact angle of a to 2a is a conductor-insulating piece contact pair, and the contact pairs with contact angles of 0 to a and 2a to 360 are conductor-conductor contact pairs.

[0020] In the above second aspect, the Bitter sheets DISK2, DISK3 and DISK4 are all in a superposition state of radial expansion and slit cantilever beam movement.

[0021] In the above-mentioned second aspect, the corresponding node displacement coupling conditions are applied to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model, including: coupling the corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces of the coil model respectively; setting the axial displacements of all nodes on the Bitter sheet on the lower end surface to 0, and setting all displacements of the nodes with the largest node number on the Bitter sheet on the lower end surface to 0.

[0022] A third aspect of the present disclosure provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable by the processor. When the processor executes the computer program, the method described in the first aspect above is implemented.

[0023] A fourth aspect of the present disclosure provides a computer-readable storage medium having computer-executable instructions stored thereon. When the computer-executable instructions are executed by a processor, the processor is prompted to implement the method described in the first aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a water-cooled magnet Bitter sheet in the related art;

[0025] FIG2 is a schematic diagram of the structure of a water-cooled magnet insulating sheet in the related art;

[0026] FIG3 is a schematic diagram of a lamination method of a water-cooled magnet coil in the related art;

[0027] FIG4 is a schematic structural diagram of a water-cooled magnet coil in the related art;

[0028] FIG5 is a flow chart of a method for calculating the comprehensive stress of a water-cooled magnet Bitter sheet according to an embodiment of the present disclosure;

[0029] FIG6 is an exploded view of a coil model constructed in one embodiment of the present disclosure;

[0030] FIG7 is a stress distribution diagram of DISK1 of a Bitter sheet in one embodiment of the present disclosure;

[0031] FIG8 is a stress distribution diagram of DISK3 of a Bitter sheet in one embodiment of the present disclosure;

[0032] FIG9 is a schematic structural diagram of a system for calculating the comprehensive stress of a water-cooled magnet Bitter sheet according to an embodiment of the present disclosure;

[0033] FIG10 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0035] In this document, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this document, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0036] Although the terms "first" and "second" may be used herein to describe various features or elements, these features or elements should not be limited by these terms unless otherwise specifically indicated. These terms can be used to distinguish one feature or element from another feature or element. Thus, a first feature or element described below could be referred to as a second feature or element, and similarly, a second feature or element described below could be referred to as a first feature or element, without departing from the scope of this disclosure.

[0037] As shown in FIG5 , an embodiment of the present disclosure provides a method for calculating the comprehensive stress of a water-cooled magnet Bitter plate, the method comprising steps S10 to S40 .

[0038] In step S10 , a simplified coil model is constructed using a plurality of three-dimensional Bitter sheets with slits and no helix angle in finite element analysis software.

[0039] In this embodiment, the finite element analysis software used is ANSYS.

[0040] In step S20, the coil model is meshed to obtain mesh nodes.

[0041] In step S30, the meshed coil model is subjected to boundary conditions and load conditions before simulation, wherein the boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end surfaces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, wherein the contact pairs include conductor-insulating sheet contact pairs and conductor-conductor contact pairs, and the load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force to the upper end surface of the coil model.

[0042] In step S40 , the stress distribution of the Bitter sheet is calculated based on the simulation results.

[0043] It should be noted that the related art simplifies the water-cooled magnet coil into a two-dimensional, circularly symmetric model of a Bitter sheet. This model, focusing on a single Bitter sheet, fails to calculate the effects of axial electromagnetic pressure perpendicular to the sheet plane and friction between the sheets on stress distribution. It also ignores the presence of slits in the sheet and, consequently, their effect on stress distribution. To achieve higher-precision stress distribution results and ideal computational accuracy, the complete water-cooled magnet model must be imported into finite element software (ANSYS) for simulation. However, since the water-cooled magnet coil is composed of thousands of staggered and stacked Bitter sheets and insulating sheets, the model requires a very large number of meshes, making it impossible for conventional computers to calculate.

[0044] In this embodiment, a three-dimensional Bitter sheet model with a slit and no helix angle is established in ANSYS software using the APDL language, and then a coil model is constructed based on the Bitter sheet model. When constructing the coil model, the tiny helix angle of the Bitter sheet in the coil is ignored, and contact pairs including conductor-insulating sheet contact pairs and conductor-conductor contact pairs are set on the contact surfaces between the Bitter sheets, thereby converting the helical surface contact into a planar contact and removing the insulating sheet structure. The water-cooled magnet coil structure is simplified as necessary to ensure a small computational complexity and high convergence of the finite element calculation model of the water-cooled magnet coil. Factors such as axial electromagnetic force, friction between Bitter sheets, and slits are incorporated into the stress calculation to simulate the radial electromagnetic force, axial electromagnetic force, friction between Bitter sheets, and slits on the Bitter sheet. This solves the problem of the influence of the axial electromagnetic force and slits on the stress distribution, making the calculated stress distribution of the Bitter sheet more accurate and more consistent with the actual stress distribution. This ensures that the coil model is sufficiently simplified while obtaining a more accurate stress distribution result.

[0045] Specifically, in this embodiment, the tiny helical angle of the Bitter sheet in the coil is first ignored, and a 3D Bitter sheet model with a slit and no helical angle is established in the finite element analysis software. At the same time, conductor-insulating sheet contact pairs and conductor-conductor contact pairs are set on the contact surfaces between the Bitter sheets in the boundary conditions to simulate the interaction scenario of the friction between the Bitter sheets, thereby replacing the insulating sheet structure in the coil model and simplifying the insulating sheet structure in the model. A simplified coil calculation model is formed by copying and rotating multiple 3D Bitter sheet models with no helical angle. The role of the simplified coil model is to: convert the helical surface contact into a plane contact and remove the insulating sheet structure, thereby improving the convergence of the finite element calculation; and to replace the complete coil with multiple Bitter sheets, thereby greatly reducing the amount of calculation. In addition, in this embodiment, factors such as axial electromagnetic force, friction between Bitter sheets, and slits are incorporated into the stress calculation, which solves the problem of the influence of axial electromagnetic force application and slits on stress distribution, making the calculated Bitter sheet stress distribution more accurate and more consistent with the actual stress distribution. Therefore, the comprehensive stress calculation method of the water-cooled magnet Bitter plate according to this embodiment can not only ensure that the coil model is sufficiently simplified but also solve the pain point problem of the 2D circularly symmetrical model of the Bitter plate.

[0046] In one embodiment, the method further comprises: setting the friction coefficient between the conductor-insulating sheet contact pair as the insulation contact surface friction coefficient, and setting the friction coefficient of the conductor-conductor contact pair as the conductor contact surface friction coefficient.

[0047] In this embodiment, different friction coefficients are used to define the contact surfaces between the Bitter sheets and the friction surfaces between the Bitter sheets and the insulating sheet, simplifying the insulating sheet in the coil model. Specifically, contact pairs are set between the contact surfaces of the Bitter sheets. The friction coefficient between the conductor-insulating sheet contact pair is set to the insulation contact surface friction coefficient, and the friction coefficient between the conductor-conductor contact pair is set to the conductor contact surface friction coefficient. This simulates the interaction of friction forces between the Bitter sheets.

[0048] In one embodiment, as shown in FIG6 , the coil model includes a plurality of Bitter sheets arranged sequentially from bottom to top, and the slit angle of each Bitter sheet increases by an insulation angle along the same direction.

[0049] Specifically, the insulation angle is the sector angle of the insulation sheet, which is determined according to the actual lamination of the coil.

[0050] In one embodiment, for example, five three-dimensional Bitter sheets with slits are assembled at specific angles to form a coil model, including Bitter sheets DISK1, DISK2, DISK3, DISK4 and DISK5 arranged from bottom to top, wherein the slit angles of DISK1 and DISK5 are both 180 degrees, and the slit angles of DISK2, DISK3, and DISK4 are 360-a degrees, 0 degrees, and a degrees, respectively, where a is the fan angle of the insulating sheet.

[0051] Specifically, between the Bitter sheet DISK1 and the Bitter sheet DISK2, the contact surface pair with a contact angle of 360-2a to 360-a is a conductor-insulating sheet contact pair, and the corresponding friction coefficient is fm-i; the contact surface pair with a contact angle of 0 to 360-2a and 360-a to 360 is a conductor-conductor contact pair, and the corresponding friction coefficient is fm-m.

[0052] Between the Bitter sheet DISK2 and the Bitter sheet DISK3, the contact pair with a contact angle of 360-a to 360 is a conductor-insulating sheet contact pair, and the friction coefficient is fm-i; the contact pair with a contact angle of 0 to 360-a is a conductor-conductor contact pair, and the friction coefficient is fm-m.

[0053] Between the Bitter sheet DISK3 and the Bitter sheet DISK4, the contact pair with a contact angle of 0 to a is a conductor-insulating sheet contact pair, and the friction coefficient is fm-i; the contact pair with a contact angle of a to 360 is a conductor-conductor contact pair, and the friction coefficient is fm-m.

[0054] Between the Bitter sheet DISK4 and the Bitter sheet DISK5, the contact pair with a contact angle of a to 2a is a conductor-insulating sheet contact pair, and the friction coefficient is fm-i; the contact pair with a contact angle of 0 to a and 2a to 360 is a conductor-conductor contact pair, and the friction coefficient is fm-m.

[0055] In one embodiment, applying corresponding node displacement coupling conditions to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model includes: coupling the corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces of the coil model respectively; setting the axial displacement of all nodes on the Bitter sheet on the lower end surface to 0, and limiting all displacements of the node with the largest node number on the Bitter sheet on the lower end surface to 0.

[0056] Specifically, this embodiment couples the displacements of corresponding nodes on the two surfaces of the DISK1 and DISK5 slits, that is, the displacements of corresponding nodes on the two surfaces are equal; and sets the axial displacements of all nodes on the lower end surface of DISK1 to 0, limiting all displacements of the node with the largest node number on DISK1 to 0, that is, the displacements in the x-axis, y-axis, and z-axis directions are all 0.

[0057] Specifically, a 5-disk model was constructed by assembling five Bitter sheets. The stack simulated the frictional interaction between the sheets. Disk 1 through Disk 5 served as the top and bottom sheets, respectively. Contact pairs were established between all contact surfaces in Disk 1 through Disk 5, introducing friction conditions. Disk 1 and Disk 5 were subjected to corresponding nodal displacement coupling conditions for the slits. The calculation essentially removed the slits, achieving full 360-degree continuity. The model simulated the synchronous radial expansion of Disk 1 and Disk 5 under electromagnetic force. An insulation angle was added in the same direction between adjacent sheets, Disk 2, Disk 3, and Disk 4, simulating a realistic arrangement in a coil stack. No restrictions were placed on the slits in Disk 2, Disk 3, and Disk 4, resulting in a superposition of radial expansion and cantilever-like motion of the slits.

[0058] Disk 1 is in contact with Disk 2 on only one side. Disk 1 simulates radial expansion and cantilever-like motion due to friction. Disk 2 is in contact with Disk 1 and Disk 3. Disk 2 itself expands radially and moves in a cantilever-like manner. Disk 1 expands radially, while Disk 3 expands radially and moves in a cantilever-like manner. Disk 2 simulates radial expansion on one side and cantilever-like motion on the other side due to friction. Disk 3 is in contact with Disk 2 and Disk 4. Disk 3, Disk 2, and Disk 4 all expand radially and move in a cantilever-like manner. Disk 3 simulates radial expansion on both sides and cantilever-like motion due to friction. This condition is consistent with the actual operating conditions of the bitter plate in the coil. Therefore, the stress state of Disk 3 is the actual stress state we need to wait for.

[0059] It should be noted that this embodiment simulates the radial electromagnetic force, axial electromagnetic force, friction between Bitter plates, and slits on the Bitter plate. The calculated stress distribution of the Bitter plate is more accurate and more consistent with the actual stress distribution. Figure 7 shows the local stress concentration phenomenon (gray part in the figure) formed by DISK1 under the action of friction; Figure 8 shows the distribution law of stress in the circumferential direction when DISK3 has slits.

[0060] In this example, a stack of five Bitter sheets was used to simulate the frictional interaction between the sheets. Nodal displacement coupling conditions were applied to the slits in the Bitter sheets on the upper and lower end faces of the coil model. The calculation essentially removed the slits, achieving full 360-degree continuity. This simulated the synchronous radial expansion of the Bitter sheets on the upper and lower end faces under the action of electromagnetic forces. For the Bitter sheet between the upper and lower end faces, an insulation angle was added in the same direction between adjacent sheets to simulate the actual arrangement of the coil sheets. No restrictions were placed on the slits in the Bitter sheet between the upper and lower end faces. This ensured that the operating conditions of the Bitter sheets in the coil model were consistent with those of the actual Bitter sheets in water-cooled magnet coils.

[0061] Each step of the above method can be performed by any suitable device that can perform the corresponding function. These devices may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. It should be understood that although the various steps in the flowchart shown in the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order and can be performed in other orders. Moreover, at least a portion of the steps in the flowchart shown in the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0062] 9 , an embodiment of the present disclosure further provides a comprehensive stress calculation system for a water-cooled magnet Bitter sheet, the system comprising a model building module 10 , a model partitioning module 20 , a condition applying module 30 and a stress calculation module 40 .

[0063] The model construction module 10 is used to construct a simplified coil model in the finite element analysis software using multiple three-dimensional Bitter sheets with slits and no helix angle. The model division module 20 is used to mesh the coil model to obtain mesh division nodes. The condition application module 30 is used to apply boundary conditions and load conditions to the meshed coil model and then perform simulation. The boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end faces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, and the contact pairs include conductor-insulating sheet contact pairs and conductor-conductor contact pairs. The load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force to the upper end face of the coil model. The stress calculation module 40 is used to calculate the stress distribution of the Bitter sheet based on the simulation results.

[0064] In one embodiment, the condition imposing module 30 is further configured to set the friction coefficient between the conductor-insulating sheet contact pair as the insulation contact surface friction coefficient, and set the friction coefficient of the conductor-conductor contact pair as the conductor contact surface friction coefficient.

[0065] In one embodiment, the coil model includes a plurality of Bitter sheets arranged sequentially from bottom to top, and the slit angles of the Bitter sheets increase in the same direction.

[0066] In one embodiment, the corresponding node displacement coupling conditions are applied to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model, specifically including: coupling the corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces of the coil model respectively; setting the axial displacements of all nodes on the Bitter sheet on the lower end surface to 0, and setting all displacements of the node with the largest node number on the Bitter sheet on the lower end surface to 0.

[0067] It should be noted that other embodiments or specific implementation methods of the water-cooled magnet Bitter sheet comprehensive stress calculation system disclosed in the present invention can refer to the above-mentioned method embodiments, which will not be repeated here.

[0068] The modules or units involved in the above-mentioned water-cooled magnet Bitter sheet comprehensive stress calculation system can be implemented by hardware or software. In particular, each box in the block diagram showing the water-cooled magnet Bitter sheet comprehensive stress calculation system, as well as the combination of boxes in the block diagram, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions. It is understood that the name of a module or unit does not constitute a limitation of the module or unit itself in certain circumstances. For example, "model construction module" can also be described as "module for building a model."

[0069] FIG10 schematically illustrates the structure of an electronic device according to an embodiment of the present disclosure. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable by the processor. When the processor executes the computer program, the method for calculating the comprehensive stress of a water-cooled magnet Bitter sheet described in the above embodiment is implemented. The electronic device 80 shown in FIG10 is merely an example and should not limit the functionality and scope of use of the embodiments of the present disclosure.

[0070] As shown in FIG10 , the electronic device 50 may be implemented as a computing device, such as a server device. Components of the electronic device 50 may include, but are not limited to, at least one processor 51, at least one memory 52, and a bus 53 connecting various system components (including the memory 52 and the processor 51).

[0071] The bus 53 includes a data bus, an address bus, and a control bus.

[0072] The memory 52 may include a volatile memory, such as a random access memory (RAM) 521 and / or a cache memory 522 , and may further include a read-only memory (ROM) 523 .

[0073] The memory 52 may also include a program / utility 525 having a set (at least one) of program modules 524, such program modules 524 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0074] The processor 51 executes various functional applications and data processing by running computer programs stored in the memory 52, such as the medical image reconstruction method described in Example 1 of the present disclosure.

[0075] The electronic device 50 can also communicate with one or more external devices 54 (e.g., a keyboard, pointing device, etc.). This communication can occur via an input / output (I / O) interface 55. Furthermore, the model-generating device 50 can also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 56. As shown in FIG5 , the network adapter 56 communicates with other modules of the model-generating device 50 via a bus 53. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the model-generating device 50, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, RAID (RAID) systems, tape drives, and data backup storage systems.

[0076] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0077] The present disclosure also provides a computer-readable storage medium having computer-executable instructions stored thereon. When executed by the processor, the processor is prompted to implement the method for calculating the comprehensive stress of a water-cooled magnet Bitter plate described in the above embodiment.

[0078] The aforementioned computer-readable storage medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or component. In the present disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable storage medium other than a computer-readable storage medium that can transmit, propagate, or convey a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable storage medium may be conveyed using any suitable medium, including but not limited to wires, optical cables, RF (radio frequency), etc., or any suitable combination thereof.

[0079] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present disclosure.

[0080] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A method for calculating the comprehensive stress of a water-cooled magnet Bitter sheet, characterized in that: The method comprises: A simplified coil model was constructed using 3D Bitter sheets with slits and no helix angle in finite element analysis software. Meshing the coil model to obtain meshing nodes; Applying boundary conditions and load conditions to the meshed coil model and then performing simulation, wherein the boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end surfaces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, wherein the contact pairs include conductor-insulating sheet contact pairs and conductor-conductor contact pairs, and the load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force on the upper end surface of the coil model; Based on the simulation results, the stress distribution of the Bitter sheet is calculated.

2. The method according to claim 1, characterized in that The method further includes: setting the friction coefficient between the conductor-insulating sheet contact pair as the insulation contact surface friction coefficient, and setting the friction coefficient of the conductor-conductor contact pair as the conductor contact surface friction coefficient.

3. The method according to claim 1, characterized in that The coil model includes a plurality of Bitter sheets arranged in sequence from bottom to top, and the cutting angles of the Bitter sheets increase in the same direction.

4. The method according to claim 3, characterized in that The coil model includes Bitter sheets DISK1, DISK2, DISK3, DISK4 and DISK5 arranged from bottom to top, wherein the cutting angles of DISK1 and DISK5 are both 180 degrees, and the cutting angles of DISK2, DISK3 and DISK4 are 360-a degrees, 0 degrees and a degrees respectively, where a is the fan angle of the insulating sheet.

5. The method according to claim 4, characterized in that Between the Bitter sheet DISK1 and the Bitter sheet DISK2, the contact pair with a contact angle between 360-2a and 360-a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle between 0 and 360-2a and between 360-a and 360 is a conductor-conductor contact pair; Between the Bitter sheet DISK2 and the Bitter sheet DISK3, the contact pair with a contact angle of 360-a to 360 is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to 360-a is a conductor-conductor contact pair; Between the Bitter sheet DISK3 and the Bitter sheet DISK4, the contact pair with a contact angle of 0 to a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of a to 360 is a conductor-conductor contact pair; Between the Bitter sheet DISK4 and the Bitter sheet DISK5, the contact pair with a contact angle of a to 2a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to a and 2a to 360 is a conductor-conductor contact pair.

6. The method according to claim 4, characterized in that The Bitter sheets DISK2, DISK3 and DISK4 are all in a superposition state of radial expansion and slit cantilever beam movement.

7. The method according to claim 1, characterized in that The step of applying corresponding node displacement coupling conditions to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model includes: The corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces in the coil model are coupled respectively; The axial displacement of all nodes on the lower end surface Bitter sheet is set to 0, and the displacement of all nodes with the largest node number on the lower end surface Bitter sheet is set to 0.

8. A water-cooled magnet Bitter sheet comprehensive stress calculation system, characterized in that: The system comprises: A model building module is used to build a simplified coil model in finite element analysis software using multiple Bitter sheets with 3D slits and no helix angle; A model partitioning module is used to perform mesh partitioning on the coil model to obtain mesh partitioning nodes; A condition application module, used for applying boundary conditions and load conditions to the meshed coil model and then performing simulation, wherein the boundary conditions include applying corresponding node displacement coupling conditions to the slits of the Bitter sheets on the upper and lower end surfaces of the coil model and setting contact pairs on the contact surfaces between all Bitter sheets, wherein the contact pairs include conductor-insulating sheet contact pairs and conductor-conductor contact pairs, and the load conditions include loading electromagnetic force into all nodes of the coil model and applying axial force on the upper end surface of the coil model; The stress calculation module is used to calculate the stress distribution of the Bitter sheet based on the simulation results.

9. The system according to claim 8, characterized in that The condition imposing module is further used to set the friction coefficient between the conductor-insulating sheet contact pair as the insulation contact surface friction coefficient, and to set the friction coefficient of the conductor-conductor contact pair as the conductor contact surface friction coefficient.

10. The system according to claim 8, characterized in that The coil model includes a plurality of Bitter sheets arranged in sequence from bottom to top, and the cutting angles of the Bitter sheets increase in the same direction.

11. The system according to claim 10, characterized in that The coil model includes Bitter sheets DISK1, DISK2, DISK3, DISK4 and DISK5 arranged from bottom to top, wherein the cutting angles of DISK1 and DISK5 are both 180 degrees, and the cutting angles of DISK2, DISK3 and DISK4 are 360-a degrees, 0 degrees and a degrees respectively, where a is the fan angle of the insulating sheet.

12. The system according to claim 11, characterized in that Between the Bitter sheet DISK1 and the Bitter sheet DISK2, the contact pair with a contact angle between 360-2a and 360-a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle between 0 and 360-2a and between 360-a and 360 is a conductor-conductor contact pair; Between the Bitter sheet DISK2 and the Bitter sheet DISK3, the contact pair with a contact angle of 360-a to 360 is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to 360-a is a conductor-conductor contact pair; Between the Bitter sheet DISK3 and the Bitter sheet DISK4, the contact pair with a contact angle of 0 to a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of a to 360 is a conductor-conductor contact pair; Between the Bitter sheet DISK4 and the Bitter sheet DISK5, the contact pair with a contact angle of a to 2a is a conductor-insulating sheet contact pair, and the contact pair with a contact angle of 0 to a and 2a to 360 is a conductor-conductor contact pair.

13. The system according to claim 11, characterized in that The Bitter sheets DISK2, DISK3 and DISK4 are all in a superposition state of radial expansion and slit cantilever beam movement.

14. The system according to claim 11, characterized in that The step of applying corresponding node displacement coupling conditions to the slits of the Bitter sheet on the upper and lower end surfaces of the coil model includes: The corresponding node displacements on the slits of the Bitter sheet located on the upper and lower end surfaces in the coil model are coupled respectively; The axial displacement of all nodes on the lower end surface Bitter sheet is set to 0, and the displacement of all nodes with the largest node number on the lower end surface Bitter sheet is set to 0.

15. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented. 16 . A computer-readable storage medium having computer-executable instructions stored thereon, which, when executed by a processor, cause the processor to implement the method according to claim 1 .

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