Estimation of Process Damping Coefficient Using Dynamic Cutting Force Model

A model of process damping in milling was developed in this study. The process damping is a critical parameter to increase the stable cutting region at low cutting speed to avoid chatter. The previous studies conducted experiments to estimate the process damping. Nevertheless, it is time and cost consuming. A model of dynamic cutting force was employed in this study. The plowing force generated by the flank-wave contact is considered as the main source of process damping to dissipate vibratory energy during cutting. In addition to the material properties and plowing force, the effects of chatter amplitude and wavelength, which result in the various indentation conditions and affect the coefficient of process damping, were also considered. The consideration of wavy contact surface and indentation area in this model allows quick determination of cutting stability conditions with high accuracy. The process damping coefficient estimated by the proposed model successfully represented the effect of the tool wear on chatter because of the change of tool geometry. Experiments were conducted to verify the new model.