A bond-based smoothed particle hydrodynamics considering frictional contact effect for simulating rock fracture

A bond-based smoothed particle hydrodynamics considering hybrid friction contact (BB-SPH-HFC) method is proposed to simulate the dynamic friction behavior during crack initiation and propagation in rock samples with pre-existing fractures under compressive loading. In the SPH program, the interactions between particles are transmitted through virtual bonds. According to the Mohr–Coulomb criterion and the maximum tensile stress criterion, the fracture of virtual bonds is determined to capture the crack propagation and coalescence modes during rock fracture. In addition, a hybrid friction contact (HFC) algorithm based on particle–segment friction contact (PSFC) and particle–particle friction contact (PPFC) was embedded in the BB-SPH model to simulate the friction-slip process between pre-existing fracture surfaces. In the HFC algorithm, the contact force is determined based on the ideal plastic collision assumption, and the PSFC and PPFC algorithms are used for the contact detection of the structure particles on the contact surface and structure particles at the corners, respectively. Numerical results show that the HFC algorithm is more accurate and stable than the traditional PPFC and PSFC algorithms. Finally, the accuracy and robustness of the BB-SPH-HFC method are verified by several numerical examples, and the numerical results are in good agreement with the theoretical and experimental results.