Crack–inclusion problem for a long rectangular slab of superconductor under an electromagnetic force

The interaction between a crack and an inclusion in a type-II superconductor is investigated in this paper. Using the finite element method, the crack–inclusion problem can be solved. Numerical results are presented to illustrate fracture behavior of superconductor under electromagnetic force. The magnetic behavior of the superconductor is described by the critical-state Bean model. The stress intensity factors at the crack tip are obtained and discussed for decreasing field after zero-field cooling. Numerical results show that the stress intensity factors at crack tip are always larger with an elastic inclusion than for a rigid inclusion. Because of the barrier effect of the rigid inclusion, the values of the stress intensity factors decrease when the crack approaches the inclusion. Relative to rigid inclusion and no inclusion cases, elastic inclusion leads to the largest value of the stress intensity factor at crack tip. Thus, the crack propagation is easier near an elastic inclusion and the rigid inclusion is helpful for crack arrest.