Application of the concepts of fracture mechanics to the failure of conductive cracks in piezoelectric ceramics

In the present paper, we report the success of applying the concepts of fracture mechanics to the failure of electrically conductive cracks in piezoelectric ceramics. We reexamine the charge-free zone model and the experimental results on poled lead zirconate titanate ceramics. We use the secant piezoelectric constant to describe the piezoelectric behavior at high electric field near a conductive crack tip. With this modification, the charge-free zone model provides more physical insight into the failure behavior of electrically conductive cracks in piezoelectric ceramics.