The high-temperature bulk superconductors with high critical current density are brittle, and can be damaged by large Lorentz forces and thermal stress during magnetization. Several studies have reported the failure of bulk superconductors during flux jumps. In this study, we analyzed the magnetization characteristics and mechanical response of the HTS bulk with inhomogeneous current density along the c-axis. The numerical simulation was consistent with the experimental results presented in the reference. Moreover, a flux jump occurred near the area of the pre-arrangement flux during the second pulsed field magnetization. The maximum temperature is lower than the critical temperature during the flux jump. In the mechanical analysis, the flux jump led to an abrupt change in the maximum stress of the bulk, and the maximum radial stress was significantly higher than the maximum hoop stress during the flux jump. The maximum radial stress increased with decreasing ambient temperature during the flux jump, and the maximum stress area was always near the seeded plane. Subsequently, the magnetization characteristics and mechanical response were studied for different locations of the seeded surface, two concentric superconducting bulks, and non-uniform fields.

中文翻译：

---

脉冲场磁化下非均匀高温超导体的磁通跃变和机械响应


具有高临界电流密度的高温块体超导体是脆性的，并且在磁化过程中会被大的洛伦兹力和热应力损坏。一些研究报告了体超导体在通量跳跃期间的失效。在本研究中，我们分析了沿 c 轴电流密度不均匀的高温超导块体的磁化特性和机械响应。数值模拟与参考文献中的实验结果一致。此外，在第二次脉冲场磁化期间，在预布置磁通区域附近发生了磁通跳跃。通量跳跃期间的最高温度低于临界温度。在力学分析中，磁通跳跃导致体体最大应力发生突变，且磁通跳跃期间最大径向应力明显高于最大环向应力。通量跳跃期间最大径向应力随着环境温度的降低而增加，并且最大应力区域始终位于种子平面附近。随后，研究了籽晶表面不同位置、两个同心超导体和非均匀场的磁化特性和机械响应。