Configurational forces and the application to dynamic fracture in electroelastic medium.

Aimed at a fresh look onto the defect mechanics of electroelastic medium, the configurational force approach is developed for these materials. The notion of working is defined in a more general framework by introducing the conjugates of configurational force and the evolution velocity of migrating control volume. The balance of configurational forces is established through the invariance condition of working under the change of material observer. Eshelby relation is identified by using the invariance requirement of configurational working under reparameterization of the motion of the boundary of migrating control volume. Energy dissipation concentrated at crack tip is evaluated through the generalized mechanical version of the second law of thermodynamics applicable to migrating control volume. Theoretical investigation shows that the negative projection of the internal configurational force concentrated at the crack tip along the direction of crack propagation plays the role of energy release rate which depends on constitutive response of materials and is independent of the energy of free electric field. [ABSTRACT FROM AUTHOR]