An improved smoothed particle hydrodynamics method for simulating crack propagation and coalescence in brittle fracture of rock materials.

• An improved SPH (ISPH) method is proposed to simulate brittle fracture of rock. • The prefabricated node segment (PNS) method can generate arbitrarily complex flaws. • The open flaw prefabricated by the PNS method does not cause kernel truncation. • Coupled dynamic buffer SBT algorithm can effectively suppress the end effect. • Coupled dynamic buffered SBT algorithm is convenient to apply mechanical boundaries. A new meshless numerical method, namely the improved smoothed particle hydrodynamics (ISPH) method, is proposed to simulate the fracture process of rock samples with pre-existing flaws under uniaxial compression. By improving the kernel function of SPH method, the brittle fracture characteristics of materials are presented. In ISPH, a prefabricated node segment (PNS) method is used to generate arbitrarily complex flaws, which avoids the division and distortion of traditional particles. In order to further improve the numerical accuracy, a new solid boundary treatment method called coupled dynamic buffer SBT algorithm is applied to ISPH, which is verified to be effective and robust via two benchmark samples. The effect of the length of a pre-existing flaw on the fracture mode and compressive strength of the rock sample is studied by using the elastic-brittle constitutive model. The numerical prediction results are in good agreement with the experimental observations. In addition, the effect of the unconnected rate on the crack propagation and coalescence mode of a rock sample with two pre-existing flaws under uniaxial compression is also studied. The numerical simulation results are in good agreement with the experimental results, which further verify the accuracy and superiority of the ISPH method. [ABSTRACT FROM AUTHOR]