Nonlinear behaviour of interacting dielectric cracks in piezoelectric materials

Existing studies on the fracture of cracked piezoelectric materials have been limited mostly to the electrically impermeable and permeable crack models, which represent the limiting cases of the physical boundary condition along the crack surfaces. This paper presents a study on the electromechanical behaviour of interacting dielectric cracks in piezoelectric materials. The cracks are filled with dielectric media and, as the result, the electric boundary condition along the crack surfaces is governed by the opening displacement of the cracks. The formulation of this nonlinear problem is based on simulating the cracks using distributed dislocations and solving the resulting nonlinear singular integral equations. Multiple deformation modes are observed. A solution technique is developed to determine the desired deformation mode of the interacting cracks. Numerical results are given to show the effect of the interaction between parallel cracks. Attention is paid to the transition between permeable and impermeable models with increasing crack opening.