Accurate Prediction of Cutting Force and Force-Induced Deformation in End Milling of Titanium Alloy Thin-Walled Parts Considering Tool Wear and Material Removal

Titanium alloy thin-walled parts are widely used in the aerospace industry because of their excellent high-temperature performance. However, their low structural stiffness and poor machinability often result in substantial machining deformation and severe tool wear, thereby reducing machining accuracy and surface quality. To address these issues, an accurate method is proposed for predicting cutting force and force-induced deformation in the end milling of titanium alloy thin-walled parts while considering tool wear and material removal. First, a cutting force model incorporating tool wear is established to characterize the influence of tool wear on milling forces during titanium alloy machining. Subsequently, a force-induced deformation model is developed based on small-deflection theory to describe the deformation response of the flexible workpiece under milling loads. Furthermore, an iterative strategy is proposed to predict the coupled evolution of cutting force and force-induced deformation during successive material removal. In this strategy, the element stiffness matrix is updated at different feed positions according to the evolving material removal state, while the effects of workpiece deformation on the actual cutting state are incorporated into the cutting force calculation. This provides a framework for accurately predicting cutting force and force-induced deformation. Multilayer end-milling experiments were conducted for validation. The average peak-value errors of Fy and Fz were 7.8% and 5.5% for the new tool and 5.9% and 6.1% for the tool with VB = 0.05 mm, respectively, while the corresponding average deformation prediction errors were 11.8% and 14.5%. These results demonstrate the accuracy of the proposed method.