Fracture criteria of piezoelectric ceramics with defects

In this paper, based on a solution of an elliptic cavity in piezoelectric ceramics with uniform loading at infinity, we analyze the stress and electric fields in the limit cases of the solution when the elliptical cavity tends gradually to a crack. The result in the zone near the crack tip is different from the result in the zone far away from the crack tip. The calculation results of a PZT-4 material are presented. Two new fracture criteria are...