A phase-field model for fracture in piezoelectric ceramics

A phase-field model is presented for modeling the fracture of piezoelectric ceramics. The implementation of several different crack face boundary conditions, including conducting, permeable, and insulating or impermeable, as well as energetically consistent is described. The approach to the latter involves a finite deformation framework for piezoelectricity. In addition, a new function that governs material degradation is proposed to eliminate the presence of high phase-field values in the vicinity of large electric fields. The new function is found to lead to improved brittle material behavior as well. Results are presented that demonstrate the capability of the model to capture complicated phenemona that arise in piezoelectric fracture, including crack retardation, acceleration, and turning.