Energy Release rate and crack propagation in piezoelectric materials. Part I: Mechanical/electrical load

Abstract

A finite element technique is used to study the angular distribution of the energy release rates for crack propagation in a piezoelectric ceramic because of a mechanical or electrical load. Comparisons are made between the energy release rate and the maximum stress criteria for the crack propagation. Substantial differences are found in the mode of crack propagation based on these two criteria. Significant differences in the energy release rate are found between applied stress and applied strain, and between applied electric displacement and applied electric field. For applied electrical loads, oblique crack propagation, experimentally seen by McHenry and Koepke, is explained by the energy release rates.