Improvement of orthogonal cutting simulation with a nonlocal damage model

In this paper, the implementation of a nonlocal gradient damage formulation is described which aims to improve the reliability of the numerical prediction of orthogonal cutting simulations. The major concerns are accuracy of computational results, independence of element size, modeling of failure phenomenon for cutting process simulation and proposing reliable and stable separation criteria for orthogonal metal cutting. To avoid pathological localization and mesh dependence and to incorporate length scale effects due to microstructure evolution, the damage growth is driven by a nonlocal variable with a second order partial differential equation. Two governing equations, i.e. equilibrium and nonlocal averaging equation, are solved simultaneously. The results are presented to show the effect of the nonlocal damage model on separation criterion, cutting force, width of shear band, and effect of material length scale to make results mesh independence. The Johnson-Cook damage criterion is used to compare local and nonlocal model results. Numerical simulations are validated through comparison the cutting force in the nonlocal damage model with the cutting force measured by experiment results taken from literature. (C) 2012 Elsevier Ltd. All rights reserved.