A crystal plasticity model for ferroelectrics

A micromechanical constitutive model for a ferroelectric crystal of the per ovskite type is developed. The model uses a crystal plasticity formulation in which transformation between crystal variants is treated in the same way as slip on a crystal slip system. The volume fractions of the crystal vari ants are used as variables which represent the state of the crystal, The di electric hysteresis and "butterfly" hysteresis of a single crystal under lo w frequency cyclic electric fields are presented. Estimates of the response of a ferroelectric polycrystal to the same loading are calculated using a self-consistent mean-field homogenization scheme.