This paper presents an updated full-discretization method for milling stability prediction based on cubic spline interpolation. First, the mathematical model of the time-delay milling system considering regenerative chatter is represented by a dynamic delay differential equation. Then, in a single tooth passing period, the time is divided into a finite time intervals, the state item and the time-delay item are approximated in each time interval by cubic spline interpolation and third-order Newton interpolation, respectively. Afterward, a transition matrix is constructed to represent the transfer relationship of the teeth in a period. Finally, based on Floquet theory, the milling stability lobes can be obtained. Meanwhile, in order to improve computational efficiency, an optimized method is proposed based on the traditional algorithm and the proposed method has high precision without losing high efficiency. Finally, several milling experiments are conducted to verify the accuracy of the proposed method, and the results show that the predicted results agree well with the experimental results.

Machining deformation is a key bottleneck that restricts the improvement of manufacturing accuracy of aviation thin-walled structural components, such as frames, beams, and wall panels. The initial residual stress of the workblank and the cutting load are the direct factors leading to machining deformation. Based on the initial residual stress measurement and the milling force test, a finite element prediction model for milling deformation of frame-type thin-walled parts with integrated consideration of initial residual stress and the milling force was established and experimentally verified in this study. Then, the influence of milling process factors, such as the frame processing sequence (FPS), the cutting path, and the single frame one-time removal depth (SFORD), on the milling deformation of frame-type parts was studied. The results showed that the established prediction model had high reliability and the prediction accuracy was improved by 6.7% compared with that when only considering the initial residual stress. A smaller machining deformation can be achieved through the use of the FPS to prioritize the width, direction, and symmetrical milling, as well as the inner loop cutting path, and the smaller SFORD. This study can provide a technical reference for the prediction and control of milling deformation of aviation thin-walled structural parts, especially frame-type thin-walled parts.