Mineral failure behavior and erosion in sandstone by abrasive waterjet using material point method

An abrasive water jet (AWJ) has significant application potential in underground engineering. However, reports on the damage behavior of abrasives and high-pressure water on sandstone minerals are rare, and the coupled rock-breaking processes and mechanisms remain unclear. This study discusses the limitations of current AWJ simulation methods and the advantages of the material point method (MPM). Two realistic heterogeneous sandstone models were constructed, and AWJ experiments and numerical simulations were conducted. The stress transmission characteristics of the AWJ and the minerals’ damage behavior were elucidated, explaining the AWJ’s rock-breaking mechanism. The results showed the following. (1) The impact of abrasives caused stress concentration and mineral fracture, leading to shear failure. Stress wave diffusion resulted in energy transmission in the elastic region. The energy was dissipated when the material exhibited plastic damage. (2) The heterogeneity of materials and structures significantly affected the stress distribution. Minerals with higher mechanical strength responded more strongly to stress, and defects (pores, weak planes) in the rock became stress concentration regions during loading. (3) The water wedge effect caused weakness-driven failure. The cracks propagated along mineral interfaces or penetrated weaker minerals on the impacted surface. (4) The water wedge loosened minerals and created irregular fracture surfaces on the impacted face while applying sustained tensile forces. Thus, the abrasive particles efficiently removed the loosened material. • Two realistic heterogeneous sandstone models were constructed based on TESCAN Integrated Mineral Analyzer (TIMA) test results. • The simulation of sandstone damage caused by an abrasive water jet, using the material point method (MPM) was conducted. • The present study elucidates the stress transmission and damage characteristics of heterogeneous sandstone impacted by an abrasive water jet. • The mechanisms of failure and erosion of sandstone minerals under an abrasive water jet were elucidated.