Electromagnetic and mechanical properties are crucial components of high-temperature superconducting magnet in high-field applications. In this research, in order to predict the multi-field behaviors of REBCO coils during the ramping process, the coupled electromagnetic-mechanical model is constructed with consideration of the strain and magnetic field dependences of the critical current of coated conductors (CCs). The 3D modelling is used to characterize the longitudinal in-homogenous critical current of a CC, which also allows for handling the coil with local defects. To verify the reliability of the coupled model, a comparison of numerical simulations with experiments for a small REBCO coil is first performed with special attention on the hoop strain evolution during the magnetization process. On this basis, the coupled model is then utilized to study the influences of local critical current non-uniformity defined by a Gaussian statistical distribution. The numerical analysis shows that, the tape inhomogeneity has an obvious impaction on decreasing the critical current of REBCO coil. And in high-field scenario, the calculated critical current of coil is highly reduced when the mutual interaction between electromagnetic and mechanical fields is considered. Afterwards, a detailed comparative study is carried out in studying the screening current effects of REBCO coil with and without taking the tape inhomogeneity into account. Finally, the effects of cooling-down process, co-winding materials and local defects are investigated to understand their role in electromagnetic-mechanical response of high-field REBCO coils.

中文翻译：

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涉及磁带不均匀性的 REBCO 线圈耦合电磁-机械响应的 3D 建模

电磁和机械性能是高温超导磁体在高场应用中的重要组成部分。在这项研究中，为了预测 REBCO 线圈在斜坡过程中的多场行为，在考虑涂层导体 (CC) 临界电流的应变和磁场依赖性的情况下构建耦合电磁-机械模型。3D 建模用于表征 CC 的纵向非均匀临界电流，这也允许处理具有局部缺陷的线圈。为了验证耦合模型的可靠性，首先对小型 REBCO 线圈的数值模拟与实验进行了比较，特别注意磁化过程中的环向应变演化。以这个为基础，然后利用耦合模型研究由高斯统计分布定义的局部临界电流不均匀性的影响。数值分析表明，胶带不均匀性对降低REBCO线圈的临界电流有明显影响。并且在强场场景下，考虑到电磁场和机械场之间的相互作用，线圈的计算临界电流大大降低。然后，在考虑和不考虑磁带不均匀性的情况下，对 REBCO 线圈的屏蔽电流效应进行了详细的比较研究。最后，研究了冷却过程、共绕组材料和局部缺陷的影响，以了解它们在高场 REBCO 线圈的电磁-机械响应中的作用。