Finite-Element Analysis of the Parameters of Fracture in a Piezoelectric Bimaterial with Interface Crack for Various Types of Boundary Conditions on its Faces

By the finite-element method, we study the stress-strain state of an interface crack in a piezoelectric bimaterial polarized in the direction perpendicular to the crack faces and subjected at infinity to the action of an electric field parallel to the crack and stresses parallel to the axis of polarization. On the crack faces, we consider the main versions of electrostatic boundary conditions, namely, impermeability (insulation), electric permeability, electric conductivity, and also a version of mixed boundary conditions, i.e., electric conductivity of a middle part of the top face and insulation of the remaining part of the crack. The formation of zones of mechanical contact between the faces is possible. The problem is considered in the statement of plane deformation. The energy release rates are found with the help of the virtual crack closure integral method. It is shown that the type of boundary conditions strongly affects the parameters of fracture.