An analytical force prediction model for turning operation by round insert considering edge effect

Abstract As a common type of ceramic inserts, the round inserts with high hardness and super high wear resistance are now widely used in high efficiency machining of some key components of aviation industry and nuclear industry. Cutting forces have an important effect on the surface quality of key components and tool life of inserts in machining process. However, the lack of understanding on the complex geometry and detailed description of uncut chip thickness (UCT) restrict the cutting force prediction of round inserts. In this paper, an analytical model for cutting force prediction of round inserts based on the precise cutting geometry is presented. First, a new geometric method for the cutting edge discretization of ceramic round insert in high speed turning is proposed. Different from the previous methods, the discretization of cutting edge in this research is performed on the rake face rather than the reference plane, which makes the prediction more accurate for the reason that the projection of tool edge is ellipse on the reference plane. Second, the shear flow stress in the primary deformed area, used to estimate the cutting force coefficients, is calculated based on the unequal division shear zone model. Then, a new prediction model considering shear flow stress and chamfer length is developed in edge force coefficients forecasting and is verified by the simulation of finite elements method (FEM). Finally, a series of cutting experiments are implemented to verify the feasibility of the proposed analytical model for cutting force prediction of round inserts. It indicates that the forecast results are in good agreement with the measured cutting forces, which proves the correctness and accuracy of the model.