Abstract
Considering a defect to be a notch filled with an electrical inclusion, path-independent integral expression of CED in arbitrary direction and its each mode contributions for piezoelectric material was derived first. Subsequently, relation between CED in arbitrary direction and energy release rate is clarified and their approximate expression is derived by employing the singular solution around crack tip. By using ε^<MI>_ψ and ε^<MII>_ψ, mode I and mode II contributions of mechanical CED in arbitrary direction, as crack parameters, effects of electric field and crack surface boundary conditions on ε^<MI>_ψ and ε^<MII>_ψ are discussed.
