Domain switch toughening in polycrystalline ferroelectrics

Mode I steady crack growth was analyzed to determine the toughening due to domain switching in ferroelectric ceramics. A multi-axial, electromechanically coupled, incremental constitutive theory is applied to model the material behavior of the ferroelectric ceramic. The constitutive law is then implemented within the finite element method to study steady crack growth. The effects of mechanical and electrical poling on the fracture toughness are investigated. Results for the predicted fracture toughness, remanent strain distributions, and domain switching zone shapes and sizes are presented. Finally, the model predictions are discussed in comparison discrete switching models and to experimental observations.