Regenerative chatter reduction through passive damping: Numerical evaluation

Regenerative chatter is a major limitation to the productivity and quality of machining operations; therefore, strategies for its suppression should be considered and evaluated during the machine design process. The regeneration of chip thickness, which is related to phase between the modulations left on the surface during the successive cuts, is the most common reason behind the phenomenon of chatter instability. Structural damping has a proportional relationship with stability limit. In this way, in order to increase the stable depth-of-cut, damping can be increased in the system by active or passive means. In this work, the use of piezoelectric shunt damping for passively improving the stability limit in turning process is numerically investigated. Firstly, the proportional relation between structural damping and stability limit is explained. Secondly, an electromechanical model including the tool-holder, piezoelectric layer and shunt circuit is obtained. And finally, different shunt damping circuits are investigated. From the numerical results, it can be concluded that the use of piezoelectric shunt damping is indeed an alternative for chatter reduction in turning operations.