Microstructural modeling of ferroelectric fracture Original Research Article

We present a microstructural model for ferroelectric ceramics based on the domain-level events occurring at the Curie transition point. Spontaneous polarization and strain are represented by discrete electric dipoles and force couples, respectively, affixed to an isotropic background medium. The fields of these point defects cause local domain interactions, and their orientations are made to switch when an electromechanical energy threshold is exceeded. The model accurately reproduces the hysteresis curves, butterfly loops, and other fundamental aspects of typical ferroelectric material behavior. In addition, by simulating domain switching near a crack tip, we predict the previously unexplained decrease in apparent fracture toughness with applied voltage that has been observed in the laboratory.