发表机构
Institute of Electrical Engineering, Slovak Academy of Sciences（斯洛伐克科学院电气工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对40 T级SuperEMFL磁体的金属绝缘嵌套式REBCO插入磁体，开发全耦合电磁-热-力学模型，采用改进的数值方法，可高效研究磁体的温度梯度、应力及临界电流退化等特性。
AI 中文摘要
超高场REBCO磁体工作在强耦合的电磁、热和力学条件下，其中屏蔽电流、局部加热、热膨胀和洛伦兹力会同时改变结构状态和导体的临界电流密度。本研究针对为40 T级SuperEMFL磁体设计的金属绝缘嵌套式REBCO插入磁体，开发了耦合电磁-热-力学模型。现有电磁公式可求解REBCO带材中的非均匀屏蔽电流；热模型从显式有限差分法（FDM）扩展为带皮卡迭代的隐式后向欧拉格式，同时引入基于BiCGSTAB的新型轴对称力学有限差分求解器，用于计算线圈绕组和G10间隔区域的位移、应变及应力。模型纳入了热膨胀和洛伦兹力的贡献，且计算得到的纵向机械应变会通过依赖应变的临界电流密度反馈至电磁模型，该临界电流密度还与温度、磁场及其取向相关。研究采用文献报道的抛物线-威布尔模型来模拟REBCO导体的可逆与不可逆应变退化。对数值方法进行了基准测试，所构建的框架为研究全尺寸嵌套式高场REBCO磁体中的温度梯度、热-力学应力、应变依赖的临界电流退化及失超行为提供了计算高效的方法。
英文摘要
Ultra high field REBCO magnets operate under strongly coupled electromagnetic, thermal and mechanical conditions, where screening currents, localized heating, thermal expansion and Lorentz forces can modify both the structural state and the critical current density of the conductor. In this work, a coupled electromagnetic, thermal and mechanical model is developed for a metal-insulated nested REBCO insert designed for a 40 T class SuperEMFL magnet. The existing electromagnetic formulation resolves the non-uniform screening currents in the REBCO tapes. The thermal model is extended from an explicit Finite Difference Method (FDM) to an implicit Backward Euler scheme with Picard iteration, while a new axisymmetric mechanical FDM solver based on BiCGSTAB is introduced to calculate displacements, strains and stresses in the coil windings and G10 spacer regions. Thermal expansion and Lorentz force contributions are included, and the calculated longitudinal mechanical strain is coupled back to the electromagnetic model through a strain dependent critical current density, which also depends on temperature, magnetic field, and its orientation. A literature-informed Parabolic-Weibull model is used to model reversible and irreversible strain degradation of the REBCO conductor. The numerical methods are benchmarked, and the resulting framework provides a computationally efficient approach for investigating temperature gradients, thermo-mechanical stresses, strain-dependent critical current degradation and quench behaviour in full scale nested high field REBCO magnets.
