Numerical study of smoothed particle hydrodynamics method in orthogonal cutting simulations - Effects of damage criteria and particle density

This paper conducts a numerical study of smoothed particle hydrodynamics (SPH), a mesh-free method, for orthogonal cutting simulations of both ductile and brittle materials. Finite element method (FEM) is commonly used for cutting simulations, but issues with excessive element deformation hinder its applications. SPH can be an alternative option because of the particle-based algorithm eliminating the use of volumetric elements. However, studies have reported inconsistent ways to set up damage definition and particle density. This paper instructs a method to build an SPH model and compares the results with an equivalent FEM, in terms of the effects of damage definition and particle density on chip morphology and cutting forces. The materials used for this study are aluminum, which represents a common ductile engineering material, and the cortical bone representing a brittle counterpart. The results reveal that in spite of the natural separation of SPH, proper damage criteria must be defined for the model accuracy. SPH tends to produce a lower cutting force than that of FEM. SPH and FEM have an opposite convergence trend as the particle density and mesh size reduce. SPH better simulates fragmented debris in brittle cuttings but fails to produce curled chips in ductile cuttings.