Modeling of milling force in multi-axis machining process for thin-walled sculptured surface

Ball-end milling is the preferred machining method for machining thin-walled sculptured surfaces as a method with higher efficiency and accuracy. However, with the change of tool attitude during the machining process, the cutter workpiece engagement (CWE) area and the instantaneous undeformed chip thickness (IUCT) will change at the same time, which makes it more difficult to accurately predict the milling force. In this paper, in order to accurately predict the milling force for multi-axis machining, the real CWE area is determined using the upper and lower boundary ideas and based on the optimization criterion. Subsequently, the IUCT model based on the infinitesimal point outer normal vector is proposed by considering the factors of tool attitude change and tool run-out, which avoids complicated iterative calculations. Finally, relying on the thin-walled sculptured surface machining experiments, a series of validation experiments were carried out under different cutting conditions, and the results show that the experimental data and the simulated data have good consistency in shape and size, which proves the validity and accuracy of the model and achieves a better result in terms of applicability, and provides a new way of thinking for the machining of sculptured surface thin-walled parts in real industrial scenarios.