Modeling of orthogonal cutting process of A2024-T351 with an improved SPH method

Abstract

Modeling the cutting process is traditionally based on the finite element method (FEM). All element-based numerical methods, however, have difficulties in handling with extremely large deformation and material fragmentation that always occur in cutting processes. In contrast, mesh-free methods such as smoothed-particle hydrodynamics (SPH) have a lot of attractive features in solving extremely large deformation problems. This work introduces first an improved SPH method and then applies it to further develop a cutting model for A2024-T351 materials to predict cutting forces and chip morphology under different cutting conditions. The improvement to the traditional SPH is achieved through modifying schemes for approximating density (density correction) and kernel gradient (kernel gradient correction). The simulation results demonstrate the improved SPH is more stable and accurate compared with the traditional SPH that is implemented in the commercial code LS-DYNA® and element-based numerical methods in FEM models. Numerical tests show that the improved SPH cutting model better explains the shear-localized chip formation and correctly estimates the chip morphology as well as the cutting forces.