A Predictive Model for Determining the Location of Chatter Onset in Turning a Slender Workpiece

Chatter is often encountered in machining processes, which reduces the geometric accuracies and dynamic stability of the cutting system. This study was motivated by the fact that chatter arising is generally related to the cutting position during straight turning of slender workpieces, which has seldom been investigated systematically in literature. In this paper, we present a predictive chatter model of turning a tailstock supported slender workpiece including the effect of the cutting tool movement along the longitudinal axis of the workpiece during cutting. Based on linear stability analysis and stiffness distribution at different cutting positions along the workpiece, an entire stability chart for a single cutting pass is constructed. By using this stability chart the critical cutting condition and the chatter onset location can be determined, and the inference of chatter lasting effect that when chatter occurs at some cutting location it will continue for a period of time until another specified location is reached, can also be drawn. Experimental trials were conducted to test the chatter model. The experimental observation was in good agreement with the theoretical inference. The difference between the predicted tool locations and the experimental results was within 9 percent at high speed cutting.