Double-edged cutting simulation with a new combined constitutive model for AISI 1045 steel

Abstract

Due to chip-flow interference and coordination, the two types of chips formed in the processes of double-edged cutting make a remarkable difference to cutting force components, tool service life, and machined parts quality. However, the chip formation mechanisms of both types are poorly understood, and the existing constitutive models generally fail to capture the deformation characteristics of the workpiece material during double-edged cutting. To this end, a new combined constitutive model composed of plasticity and damage parts is presented and applied to the finite element (FE) model for double-edged cutting of AISI 1045. The plasticity part considers the impacts of strain, strain rate, and temperature on the flow stress of workpiece material. The damage part considers the effects of stress states on the equivalent plastic strain at damage initiation. Double-edged cutting simulations were carried out employing the combined constitutive model and the Johnson-Cook (JC) model, respectively. To validate the presented constitutive model, experiments for double-edged cutting of AISI 1045 were completed, and the predicted results were compared with experimental results. It is concluded that the presented constitutive model substantially enhances the predicting accuracy for chip morphologies and cutting force components compared to the JC model. In addition, the two types chip formation mechanisms in double-edged cutting are revealed through analyzing the chip generation in simulations and the chips collected from the experiments. The new combined constitutive model contributes to the simulation-based optimization of the tool/process parameters in double-edged cutting to reduce the cutting forces or produce the desired chip morphology.