ABSTRACT
The dynamic interactions between the cutting tool and the workpiece affect directly both the quality and productivity of the metal cutting, and this can also cause an uncontrolled rise of vibration in the system. Although the conditions for instabilities in some cases can be satisfactory explained by linear dynamics, the overall interactions between the machine tool (MT) and the cutting process (CP) have to be studied as nonlinear. As an example of such behavior, the self-excited oscillations (chatter) may be given. Despite of the fact that there have been several theories put forward to explain them, no sufficient agreement between different investigators has been reached yet (e.g. Refs l-3). It is believed that the reason for these divergences is due to the approach, which treats the dynamics of the machine tool and cutting process separately. The simplest case, which questions the validity of this assumption, is the intermittent cutting process [4]. Fundamentally, there are two different kinds of chatter: the primary chatter and the secondary chatter. The primary chatter is caused primarily by the frictional effects of the chip acting on the rake surface where, due to a relative motion between the workpiece and tool, a difference exists between static and dynamic frictions. The secondary chatter is predominantly an outcome of the regenerative effect where the workpiece profile from the previous pass has some similarity to the profile of the next pass [5].
