A slip-line field model for independently characterizing shearing and ploughing effects in metal cutting processes

This study proposes a new slip-line field model to separately characterize the shearing-included cutting process and the pure-plough cutting process. The shear plane and dead metal zone in relation to the shearing effect are modelled by straight slip-lines, while the deformation area in relation to the ploughing effect is treated to have straight boundaries. The boundaries of the dead metal zone and ploughing area are determined by considering tool-workpiece frictional behaviours. The stresses acting on the boundaries of the ploughing area, dead metal zone and shear plane are separately modelled considering the thermal–mechanical coupling effect. Based on the minimum energy principle, the shear angle is originally modelled by following the dynamic requirement of chip flow to balance the forces acting on dead metal zone, shear plane and rake face. By iteratively solving the coupling effect among the temperature, stress and shear angle, the total cutting forces are acquired by integration operation through straight slip-lines. Experiment results and finite element simulations validate the proposed slip-line field model in predicting the shear angle and cutting forces for both micro and regular milling processes.