Mechanistic Modeling of Milling Process Damping Including Velocity and Ploughing Effects

In this study, a practical method for modeling of process damping in milling process is presented. The cutting forces are decomposed into two components, i.e., the shearing and ploughing forces. The tangential and radial shearing forces are modified considering the direction changing of cutting velocity. With the assumption of small amplitude vibration, ploughing forces are simplified as linear forms through introducing equivalent viscous damper. The effect of cutting velocity and the equivalent viscous damper are integrated into milling forces model since they all have contributions to process damping. The equation governing the dynamics of the milling system is constructed to predict the stability lobe. The prediction is verified by previous researchers' experiments. It is shown that when the proposed process damping model is taken into consideration, the accuracy of stability prediction can be improved significantly at low cutting speeds.