Analysis of indentation cracking in piezoceramics

The electric ®eld can signi®cantly a€ect the growth of Vickers indentation cracks in piezoceramics. In this study, the wedge e€ect caused by inelastic deformation was proposed to explain the phenomenon. An approximate analytic solution for a half penny-shaped crack in a piezoceramic half space was derived from modifying full penny-shaped crack solution according to proper boundary conditions on the free surface of the indented piezoceramic specimen. The solution in conjunction with the mechanical strain energy release rate was used to quantitatively account for the e€ect of electric ®eld on crack length produced by Vickers indentations with various indentation forces. The proposed model was able to explain the e€ects of electric ®eld on crack growth in piezoceramics