A hybrid phase-field method for modeling mixed-mode fractures in elastoplastic rock-like materials

Abstract

The phase-field method has been proven to be a powerful tool for predicting complex crack patterns and widely utilized in many fields. To effectively characterize and depict the complex cracking behaviors of rock-like materials, however, is still a challenge. In this study, a modified phase field model for mixed-mode fractures in rock-like materials is proposed. The effect of plastic free energy on damage is taken into consideration by developing a new phase field evolution equation. A non-associative Drucker–Prager constitutive model is coupled within the framework to capture more accurate stiffness and plastic strain in rock-like materials. To solve the coupled problem more efficiently, an accelerated monolithic iteration method has been developed. Several numerical results are presented to examine the viability of the established phase field model. Additionally, the investigation of the local stress field is done to identify the main driving forces of the different fracture modes.