A phase-field fracture model for piezoelectrics in hydrogen-rich environment

Piezoelectric materials are often serviced in various extreme environments and exhibit complex fracture behaviors. Past studies usually focus on the electro-mechanical coupling behavior of piezoelectric materials, ignoring the influence of environmental factors. In this paper, a phase-field model for brittle fracture in piezoelectrics under hydrogen-rich environment is developed, and the coupling effects among the elastic, electric and chemical fields have been considered. A phenomenological model is developed to characterize the deterioration of fracture toughness in hydrogen-rich environment. To solve this problem numerically, a robust staggered scheme is proposed via a hybrid manner. Numerical simulations are performed to discuss the influences of hydrogen concentration and external electric field on the fracture behaviors of piezoelectrics. It is found that the existence of hydrogen atoms will reduce fracture loads and promote the cracking of piezoelectric specimens significantly. This study will provide theoretical support for the reliability assessment of piezoelectric devices in hydrogen-rich environment.