Numerical Investigation of the Rock‐Breakage Characteristics Under the Continuous Impingement of Waterjet by Using the Coupled SPH‐FEM

This study establishes a continuous waterjet material breakage model based on the coupled smoothed particle hydrodynamics (SPH) and finite element method (FEM) that is capable of simulating the long‐time waterjet‐material interaction process. The model is able to describe the splashing effect of a waterjet and is verified by laboratory experiments. Errors of the jet‐drilled hole diameter/depth/volume between the model and experiment are 8.90%, 8.40%, and 9.86%, respectively. And the hole morphology evolution and damage/pressure/stress distribution beneath the hole are revealed based on the model. Finally, the material removal mechanisms under the impact of the waterjet are discussed. Results indicated that the hole morphology transforms from the V‐shaped to the U‐shaped under the joint action of the injecting jet impacting and the splashing jet washing. A compressively damaged region occurs directly below the hole bottom and is accompanied by a tensile damaged region around it. And, a shear‐damaged region occurs beneath the hole sidewall. Besides, radial cracks that are perpendicular to the wavefront are created by the tensile stress that is caused by the spherical compression wave. This paper provides an effective way of simulating the long‐time waterjet‐material interaction problems.