Coupled CEL-FDEM modeling of rock failure induced by high-pressure water jet

The coupled Euler-Lagrange (CEL) method and finite-discrete element method (FDEM) are adopted to simulate the rock fracture process induced by high-pressure water jet and to solve the problems of highly nonlinear, fluid-solid coupling and large deformation. The water is charac-terized by the CEL model, and water can flow freely in the Euler mesh, which can better simulate the actual shape of water jets. The rock is integrated into the FEDM model, which is produced by embedding zero-thickness cohesive elements. The traction-separation criterion of the cohesive element is used to simulate the rock damage. In the simulation process of rock fracture by the water jet, infinite elements are used to realize the non-reflection boundary conditions, simulate real working conditions, and improve the calculation reliability. Furthermore, the VUSDFLD user subroutine is used to delete the elements outside the box and reduce the impact of the fallen rock debris on simulation speed, thus improving calculation efficiency. The formation process of rock impact pits and slits, as well as the velocity and distribution of water jets, are studied by comparing the simulation and experiments of water jet fixed-point impact and moving cutting. Subsequently, the fracture mechanism of rock under the water jet is revealed, presenting new possibilities for studies into rock fractures by high-pressure water jet.

Automated summary

The coupled Euler-Lagrange (CEL) method and finite-discrete element method (FDEM) are used to simulate rock fracture induced by high-pressure water jet. The simulation addresses the challenges of nonlinear, fluid-solid coupling and large deformation. The water flow is modeled using the CEL method, which allows free flow in the Euler mesh to better represent the actual shape of water jets. The rock is integrated into the FDEM model, with cohesive elements representing rock damage. The simulation includes non-reflection boundary conditions using infinite elements and a user subroutine to improve calculation efficiency by removing elements outside the region of interest. The study compares simulation and experiments to investigate the formation of impact pits and slits, water jet velocity and distribution, and the fracture mechanism of rock under high-pressure water jet.