Development of an adaptronic workpiece holder for milling operations

So called smart or adaptronic structures have demonstrated their advantages in the field of machine tools in many recent research works. In this paper an adaptronic workpiece holder, based on piezoelectric actuators, for improving vertical milling processes is presented. This device is designed to reduce the relative dynamic displacements between the tool and workpiece. In this case, the in-plane displacements in the machine table directions are considered. The main goal is to diminish self-excited chatter and also unwanted forced vibrations. Besides avoiding rough surfaces on the workpiece and decreasing tool wear it is an aim to broaden the possibilities of milling to metal removal rates beyond the stability limit of the passive machine structure. Furthermore, the system is capable of micro-positioning and dynamically influencing the workpiece surface. The results of numerical simulations and experiments on a test rig as well as on a machine tool are presented.