Abstract
Mechanical CED (Crack Energy Density) has been proposed as a parameter to describe fracture behavior of piezoelectric materials. In this paper, we show that it depends on the loading procedure, while the whole CED does not. Then, we evaluate fracture loads corresponding to experiments for PZT-4 by employing the fracture criterion based on mechanical CED and fundamentally study the effects of loading procedure on fracture load comparing the results with the experiment.