A new dynamic boring force calculation method using the analytical model of time-varying toolpath and chip fracture

Abstract

The accurate prediction of dynamic cutting force has great significance for the quality control of the boring process for deep-cavity thin-walled parts. However, most of the classic and improved cutting force models commonly neglect the mechanism analysis of dynamic cutting force, resulting in the dynamic prediction of cutting force being almost impossible. To resolve this problem, a novel analytical dynamic cutting force prediction model for the boring process was proposed to consider the time-varying toolpath and chip fracture in the machining process. The generation mechanism of dynamic cutting force was analyzed by cutting theory and mathematical formula. The theory of maximum shear stress and the law of conservation of energy were applied to derive the dynamic cutting force for an entire rotation cutting cycle. Then, the proposed dynamic cutting force model was validated using a designed boring experiment and a classical cutting force model. The compared results showed that the dynamic cutting force model based on the proposed method had good agreement with the experimental data. Meanwhile, the advantage of accurate prediction was also further demonstrated by comparing the classic cutting force model. This paper presents an analytical dynamic cutting force prediction model for the boring process considering the toolpath and chip breakage. The underlying mechanism of the dynamic change of the cutting force was studied, and data supporting the improved quality of boring deep-cavity thin-walled parts was provided.