Double-phase-field formulation for mixed-mode fracture in rocks

Cracking of rocks and rock-like materials exhibits a rich variety patterns where tensile (mode I) shear II) fractures are often interwoven. These mixed-mode usually cohesive (quasi-brittle) frictional. Although phase-field modeling is increasingly used for rock fracture simulation, no formulation available frictional fracture. To address this shortfall, here we develop double-phase-field that employs two different phase fields to describe individually. The rigorously combines the through three approaches: (i) crack-direction-based decomposition strain energy into tensile, shear, pure compression parts, (ii) contact-dependent calculation potential energy, (iii) energy-based determination dominant fracturing mode in each contact condition. We validate proposed model, both qualitatively quantitatively, with experimental data on rocks. validation results demonstrate model – combination quasi-brittle models allows one directly use material strengths measured from experiments, unlike brittle Another standout feature it can simulate, naturally distinguish between, without complex algorithms.