Chatter vibration is critical issue in cutting process, as it significantly degrades machining accuracy. Self-excited vibration is one of the most common types of chatter vibration, and it must be suppressed because it can suddenly become large vibrations. In previous studies, the dynamic stiffness of a desktop machine tool was changed by altering the tension on the breather bar without changing the cutting conditions the transition of the stability limit and the effect of suppression chatter vibration were confirmed. Furthermore, motorized control was implemented to automate the tension adjustment, and similar suppression effects were observed. However, in those studies, the stiffness was modified prior to cutting, and the effect of changing stiffness during cutting remained uninvestigated. The present study aims to evaluate the suppression effect of dynamically altering stiffness during the cutting process. To examine the feasibility of chatter suppression, a short-time Fourier transform (STFT) was applied to analyze the shift in the stability limit diagram under cutting conditions where chatter typically occurs. The effectiveness of automatic stiffness control was experimentally validated through both impact tests and cutting tests.
Takeuchi et al. (Wed,) studied this question.