Numerical study on abrasive machining of rock using FDEM method

Abstract

Rock machining has been widely used in many industries. In order to better understand the fracture and removal mechanism for rock materials during abrasive machining, a two-dimensional scratch model was developed using the hybrid finite-discrete element method (FDEM). The crack propagation during the abrasive machining process was simulated by inserting zero-thickness cohesive elements. Based on the model, the rock fragment, cutting forces as well as damage layer under different cutting parameters and abrasive angle were investigated by a simulation study. It was found that the fracture of cohesive elements was dominated by tensile loading (mode Ⅰ) at low cutting speed and cutting depth. With the increase of cutting depth and cutting speed, shear loading (mode Ⅱ) was responsible for the fracture mode of the cohesive elements in the primary chipping zone during abrasive machining of rock materials. Both the cutting forces and the thickness of damage layer increased with the increase of cutting speed and cutting depth, which is consistent with the simulation results obtained by finite element method (FEM) and discrete element method (DEM). The inertia effect in dynamic loadings was believed to be the main reason for the increase of cutting forces at higher cutting speeds. The results demonstrated the feasibility and reliability of FDEM in rock machining simulation.