Energy release rate and crack propagation in piezoelectric materials .2. Combined mechanical and electrical loads

A finite element technique is used to study the angular distributions of the energy release rates and stresses for the crack propagation in a piezoelectric ceramic because of the applied stress and applied electric field. The change in total energy is compared with the theoretical values of the energy release rates given by Pak. This change in the total energy is higher in the case of a positive applied electric field than in the case of a negative applied electric field. For high negative applied clectric fields, the strain energy of the specimen becomes negative although a remotely applied stress is tensile in nature and under these conditions, crack closure occurs. Copyright (C) 1997 Acta Metallurgica Inc.