CRFPA: A Novel Rock Fracture Process Analysis Method Coupled with Cohesive Zone Model

Abstract

To enhance the effectiveness of fracture process simulation within the Rock Fracture Process Analysis (RFPA) framework, this study proposes a cohesive-enhanced RFPA (CRFPA) method. Cohesive elements are pre-inserted along potential fracture interfaces, either globally or locally, providing modeling flexibility tailored to different simulation objectives. A dual constitutive strategy is employed: cohesive elements adopt both brittle and quasi-brittle constitutive models to accommodate a wider range of material behaviors while solid elements retain the brittle damage model of conventional RFPA. This allows accurate distinction between matrix cracking and interfacial degradation. The method is formulated within a variational framework that ensures thermodynamic consistency, guaranteeing proper energy dissipation and irreversible damage evolution throughout the entire loading history. Leveraging RFPA’s full-step iteration scheme, CRFPA achieves stable convergence while capturing progressive interface and matrix failure. Three benchmark examples, a masonry wallette shear test, a Brazilian disc splitting test, and flaw-driven crack propagation, are used to validate CRFPA method. Simulation results show strong agreement with experimental and analytical references, highlighting improvements in crack path realism, stress field resolution, and failure mode prediction compared to traditional RFPA. This study establishes CRFPA as a robust and versatile numerical framework for multi-scale fracture analysis in quasi-brittle materials.