脉冲磁场下REBCO超导体多场耦合分析

Multi-field couplingg analysis of REBCO superconductors under pulsed magnetic fields

为了深入探究REBCO超导材料在脉冲磁化后的俘获磁场、温度及应力分布特征,本文基于H法建立二维轴对称模型,求解超导圆柱在脉冲磁化过程中的磁弹性及热传导模型。结果表明在脉冲磁场上升阶段,磁通的穿透深度随着脉冲磁场的增强而增大,当t/τ=1时,磁通完全穿透超导体,表层磁通峰值达到6.95 T。在降磁阶段,超导体被磁通穿透,沿半径方向俘获磁场随着脉冲场的降低而减小。此外,通过对比降磁阶段环向热应力与总应力曲线发现,不同时刻的环向热应力在总应力中占比达到86.7%,说明REBCO超导体在脉冲磁场下,受到了热应力与电磁应力的共同作用,且超导体的应力状态主要由热应力决定。

In order to explore the capture magnetic field,temperature and stress distribution characteristics of REBCO superconducting materials after pulsed magnetization,a two-dimensional axisymmetric model was established based on the H method considering the structural symmetry of cylindrical superconductors.The magnetoelastic and heat conduction models of superconducting cylinders during pulsed magnetization are solved.The results show that in the rising stage of the pulsed magnetic field,the penetration depth of the magnetic flux increases with the enhancement of the pulsed magnetic field.The flux completely penetrates the superconductor when t/t=1,the magnetic flux reaches a peak of 6.95 T at the surface.In the decreasing stage of the magnetization,the superconductors are all penetrated by the magnetic flux.The captured magnetic field along the radius decreases with the decrease of the pulsed field.In addition,it is found by comparing the loop thermal stress and total stress curves in the demagnetization stage that the proportion of the loop thermal stress in the total stress at different moments reaches 86.7%,indicating that the superconductor REBCO is subjected to a combination of thermal and electromagnetic stresses under the environment of pulsed magnetic field action,and that the thermal stress occupies a dominant role.