Machining chatter in continuous facing under a constant nominal cutting speed: Tool vibration with time-varying delay

Abstract

This article studies regenerative chatter in single-point face-machining at nominally constant speed under continuous conditions. A temporal model for rotational speed was developed and experimentally verified. The resulting rotational time-delay was cast into the classical force feedback mechanism for chatter. A chatter model was formulated to allow slight spindle speed variation about the temporal model. The modified method of steps was then employed to solve the tool vibration in time-domain allowing one (single-degree-of-freedom) or two (2-degree-of-freedom model) vibrational modes. Exploratory facing experiments using a grooving tool were conducted on a nickel alloy workpiece. It was found that the tool was more susceptible to chatter at larger diameters. It appeared that the single-degree-of-freedom model captured the most relevant of the observed phenomena while cutting without spindle speed variation, however, neither the 1-degree-of-freedom nor the 2-degree-of-freedom models could effectively capture the experimentally observed chatter evolution characteristics while cutting with spindle speed variation.

Modelling and simulation of surface topography machined by peripheral milling considering tool radial runout and axial drift

“…It is a self-excited vibration phenomenon that occurs in the machining process, affecting the machining accuracy and the surface quality of the workpiece and causing tool breakage, workpiece scrap, and bearing damage of machine tools. 28 Therefore, the dynamic modelling and simulation of milling process, the influence of chatter on tool radial runout and axial drift, the prediction of the milling chatter stability region, and the realization of small chatter or even no chatter cutting by the optimization of cutting parameters are the current research hotspots.…”