An analysis on vibration damping in turning through passive shunt circuits using a nonlinear model

Abstract

The use of slender tool holders is inherent to boring and turning operations. As a result, large vibrations, known as chatter, may arise, resulting in poor surface finishing and decrease in the tool life. Therefore, chatter is a recurring issue that is in need of modeling and controlling in order to improve the industry's productivity. The nonlinear and cutting friction forces, together with the mode coupling that arises from a symmetric tool holder, can lead to these extreme vibrations and possibly chaotic motion under a certain set of parameters. These nonlinearities must be studied and experimentally analyzed to be considered in chatter control mechanisms in turning. It is well known that passive shunt circuits increase the system's damping and can be used to control chatter. This paper presents a simple lumped nonlinear model of the tool holder embedded to a piezoelectric patch and an analysis of such model with and without the passive shunt circuit. The set of parameters is chosen in order to simulate a chatter condition. The resulting phase diagrams are qualitatively compared to experimental data obtained from a real turning operation made using a CNC lathe. The results show that the model is capable of appropriately simulating the chatter vibration.