Chatter prediction in flank milling of thin-walled parts considering force-induced deformation

Abstract

The deformation and chatter that occur in flank milling thin-walled parts are key factors affecting the machining quality. To solve the above problems, this paper systematically studies the force-induced deformation and chatter. Predictive models that are consistent with the actual cutting process are proposed based on a deep understanding of the process. First, the continuity principle of deformation along a continuous toolpath is revealed. Based on that, a flexible deformation prediction model with accelerated convergence rate is proposed. In predicting the deformation of the next tool location, the proposed model takes the deformation value of the previous adjacent tool location as the initial iteration value. It reduces the iteration space of the prediction process and greatly improves the prediction efficiency. Then, according to the dynamic characteristics of the tool and the thin-walled part in the milling process, a multi-mode dynamic model of the tool and a multipoint contact dynamic model of the thin-walled part are established, and the milling dynamic model is obtained by coupling the above two models in modal space. Considering deformation and the removed material, dynamics of thin-walled parts and cutting parameters are modified in the milling dynamic model. To improve the chatter prediction accuracy, the milling dynamic model is solved via a method based on the extended Newton-Cotes rules. Finally, deformation and chatter experiments of flank milling thin-walled parts are performed. The experimental results validate the correctness of the proposed models.