Chatter Vibration in Turning : 1st Report, Theoretical Studies

Abstract

The chattering of machine tools is a kind of self-excited vibration, and it is essentially a problem of dynamical instability. A lathe tool under working conditions can be regarded as a dynamic system which, for certain values of its system parameters, becomes unstable and bursts into oscillations. The system parameters are determined by the static and dynamic characteristics of the machine tool structure, the geometric shapes of the tool, and the working conditions. The causes which results in chatter or chatter-free machining are the interactions of these parameters. In this 1st report, the theoretical study is developed basing on the theory of stability criterion, and the results are presented in a form of a stability-chart which gives those cutting speeds at which, for the given values of system parameters, chatter-free machining is ensured. These stability-charts are affected by the interaction of the present motion and the chatter mark produced during the preceeding revolutions.