Regenerative Effects of Orthogonal Chip Dimensions on Turning Stability of Thin-Wall Workpiece-Tool Coupled Dynamics

Machining stability of thin-wall (flexible) components plays an important role in manufacturing efficiency and final product qualities, where machining dynamics are characterized by infinite degrees of freedom distributed in both the time and spatial domains. This article presents a distributed parameter method to model the coupled workpiece-cutting tool (WP-CT) dynamics and investigate the regenerative effects of both depth and width of cut on turning stability. By accounting for the regenerative effects in both radial and axial directions of a flexible disk component, this method relaxes a commonly made assumption that the regenerative chip of the coupled WP/CT dynamics varies in the direction of chip thickness. Formulated using the energy method, the dynamic model that requires only a few dominant modes is developed to construct 3-D stability lobe diagrams in terms of width/depth of cut, rotational speed, and cutting position. The proposed modeling method, which offers a means to identify parameters of a coupled WP-CT system and predict the spatially distributed vibrations and their effects on machining stability, has been analyzed in simulation and validated with experiments.