FEM mesh-dependence in cutting process simulations

The process simulations based on FEM techniques have been investigated for many years, some fundamental problems are still unsolved, e.g. the element size effect on the computational results. In present contribution, orthogonal cutting simulations of AISI4340 steel are considered. The major concerns are accuracy of computational results, influence of element size and effects of damage model in accommodating modeling of failure phenomenon for cutting process simulations. Numerical simulations are verified with the measured values of cutting force by considering certain case of influencing cutting parameters combination taken from literature. Element size is treated to be the most influencing constituent in the cutting process simulations. The chip morphology is related to the adiabatic assumption considered in the process simulation, the feed value and the element size. The simulation results are presented by neglecting temperature effects to show the influence of failure criterion based on plastic displacement of the numerical results. Though the chip morphology and shear band formation are most sensitive to the element size, the cutting force of process simulations is hardly influenced. The formation of saw-tooth chip in the present simulations is the result of adiabatic shear band at the tool tip and propagating towards the chip's outer surface. The present work confirms that the effect of element size on computational results is reduced significantly if the failure criterion in the process simulation is controlled by a characteristic element length considered from the progressive damage model.