A Parameter Optimization Method for Chatter Stability in Five-Axis Milling

Chatter is a dynamic instability caused by the regeneration of waviness on the workpiece surface and damages the machining efficiency and product quality. For five-axis milling, the chatter stability analysis is more complicated because the cutter-workpiece engagement and the direction of the dynamic cutting force vary along the tool path. This paper presents a parameter optimization method to avoid chatter in the five-axis milling process. The dynamic milling system is modeled in each tool-path segment, and the stability is analyzed by introducing the semi-discretization method to solve the delay differential equation. In addition, the multi-frequency solution to the stability prediction for the multiple degrees of freedom spindle-cutter system and workpiece system is presented. Considering the speed and acceleration constraints of the spindle system and the feeding system, the spindle speed optimization iterative method is applied based on the chatter prediction. The verification experiment is conducted on the five-axis milling of the S-curve part to show the predictive accuracy of the chatter model and the validity of the proposed optimization method.