Antiplane fracture in a prestressed and prepolarized piezoelectric crystal

The general complex-variable solution to the equations of incremental antiplane piezoelectricity is used to solve the problem of crack propagation in a crystal in the presence of an initial stress and electric field. Remote incremental antiplane tractions are specified and an incremental traction of the same intensity is applied to the crack faces. The initial fields are shown to have a pronounced effect on the near-tip stresses and on the displacements of the crack faces. Griffith's criterion is used to determine the combination of electromechanical parameters required for incipient crack propagation.