On the stabilizing and destabilizing effects of damping in wood cutting machines

In this paper an analytical investigation of the possibility of employing damping elements to prevent chatter instability in wood machining is presented. A simplified model of a two-degree-of-freedom machine for wood cutting is first established. Then, the stabilizing effect of damping on the initially unstable and undamped system is investigated. The influence of damping on flutter and divergence instability is analyzed separately following different approaches. Some simplified assumptions are made to facilitate the analysis and a set of explicit conditions ensuring stability is found. Since the studied system is nonconservative, not only the effect of damping on the initially unstable system is investigated, but also its effect on the initially stable system. In particular, a condition preventing the destabilization of the system is achieved through the eigenvalue sensitivity analysis. The results attained might ensure important productivity improvements in real wood machining applications. (C) 2003 Elsevier Science Ltd. All rights reserved.