ENERGY-RELEASE RATES AND PATH-INDEPENDENT INTEGRALS IN ELECTROELASTICCRACK-PROPAGATION

Two energy-release rates due to quasistatic crack propagation in elect roelastic materials are obtained by using a Griffith-type energy appro ach. Their difference represents the free electric field contribution to the propagation of the crack. Appropriate conditions for mechanical and electrical fields allow us to express the energy-release as path independent integrals, already obtained by Pak and Herrmann, and by Ma ugin and Epstein. Th assumptions are verified on the solution of an an tiplane crack problem and the integrals are evaluated in terms of elec trical and mechanical stress intensity factors.