Effect of domain switching on kinking of a crack in a ferroelectric material

Crack kinking induced by domain switching in a ferroelectric material under purely electric loading is investigated. Boundaries of domain switching zones for the asymptotic problem of a semi-infinite crack under the small scale conditions are determined based on the nonlinear electric theory. Stress intensity factors induced by the domain switching are numerically evaluated using the solution of the switching zone. Numerical results of the kink angle are obtained as a function of the ratio of the coercive electric field to the yield electric field for various polarization angles. Crack kinking in ferroelectric materials subjected to a cyclic electric field is also examined. The crack in the fully poled materials branches with different directions at application of the positive and negative electric fields, respectively. The electric fatigue crack is shown to have a forked crack pattern in the fully poled materials.