Subsurface crack problems in a cubic piezoelectric material

Subsurface crack problems in a cubic piezoelectric material are considered. The problems are formulated as singular integral equations and solved by a direct numerical method. Among normal and parallel cracks, only the parallel cracks with constant electric potential boundary condition imposed on the half-space that permeable and impermeable cracks need to be differentiated. The numerical accuracy of the present results is confirmed by comparing them with known exact solutions. The influence of material properties on the dimensionless electromechanical field intensity factors is found to be through an electromechanical coupling factor introduced in the text.