Fracture behaviors induced by electromagnetic force in a long cylindrical superconductor
Fracture behaviors induced by electromagnetic force in a long cylindrical superconductor
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DOI：
10.1063/1.3456038
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发表时间：
2010-08
影响因子：
3.2
通讯作者：
J. Zeng;Youhe Zhou;H. Yong
中科院分区：
文献类型：
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作者：
J. Zeng;Youhe Zhou;H. Yong
本文研究了具有中心裂纹的长圆柱形超导体的裂纹问题。考虑了临界态的Bean模型和Kim模型，分别计算了零场冷却(ZFC)和场冷却(FC)磁化过程的应力强度因子。基于有限元方法，首先得到了不同磁场下应力强度因子的变化规律。随着外加电场的减小，应力强度因子先快速增大，达到峰值后逐渐减小。然后，对于每一长度的裂纹，计算应力强度因子的最大值。数值结果表明，FC活化过程比ZFC活化过程对应力强度因子的影响更为显著。最后，将Bean模型和Kim模型的计算结果进行了比较。当无因次参数p较小时，两种不同临界态模型的结果几乎相等。总的来说，这些结果对于理解高温超导体的临界态模型和断裂机制是有益的。
In the present work, the crack problem of a long cylindrical superconductor with a center crack is investigated. The Bean and Kim model of critical state are considered, and the stress intensity factors are calculated for zero-field cooling (ZFC) and field cooling (FC) magnetization processes, respectively. Based on the finite element method, the variation laws of the stress intensity factors for different magnetic field are obtained first. As the applied field decreases, the stress intensity factors increase quickly first, and then decrease gradually after they reach a peak value. Subsequently, for every length of the crack, the maximum of the stress intensity factor is calculated. Numerical results obtained show that, the FC activation process has more significant influence on the stress intensity factors than the ZFC activation process. Finally, the results obtained from Bean model and Kim model are compared. When the dimensionless parameter p is lesser, the results in two different critical state models are equal almost. Generally speaking, all of the results are useful for understanding the critical state model and the fracture mechanism of high-temperature superconductors.