Vibration absorber design to suppress regenerative chatter in nonlinear milling process: Application for machining of cantilever plates

In this paper, a tunable vibration absorber (TVA) is designed to suppress regenerative chatter in milling of cantilever plates. In machining industry, the majority of work-piece materials or the interaction of work-piece/cutting tool causes the cutting forces to demonstrate nonlinear behavior. The application of TVA (as a semi-active controller) is investigated for the process with an extensive nonlinear model of cutting forces. Under regenerative chatter conditions, optimum values of the absorber position and its spring stiffness are found such that the plate vibration is minimized. For this purpose, an optimal algorithm is developed based on mode summation approach. Results are presented and compared for two cases: regenerative chatter under resonance and non-resonance conditions. It is shown that the absorber acts efficiently in chatter suppression of both machining conditions, in a wide range of chatter frequencies. Moreover, using TVA leads to the great improvement in stability limits of the process. Therefore, larger values of depth of cut and consequently more material removal rate can be obtained without moving to the unstable machining conditions.