Stability analysis of thin-walled parts end milling considering cutting depth regeneration effect

Weak rigid parts are widely used in aerospace industry. These parts are characterized by thin walls. Most of these parts have the meter-level size and mesh surface, thus have a requirement for tool accessibility. Therefore, the end milling is an applicable process to reduce the thickness of these parts. Due to the weak rigidity of these parts in the normal direction, severe chatter will occur in the machining process, which will reduce the machining efficiency and spoil the machining surface, so the processing stability of the thin-walled part needs to be studied. In this paper, the dynamic model for end milling of thin-walled parts is presented. The regeneration effect in the surface normal direction is proposed, and the dynamic equation is constructed considering the vibration of the workpiece in the cutting tool axial direction. The stability lobe diagram is obtained by numerical method. It is found that the stability of weak rigid parts end milling is related to the cutting speed, the feed rate, and the width of cut, but not to the cutting axial depth. Finally, cutting experiments are conducted. The experimental result is coincident well with the prediction, thus verifying the proposed dynamic model and the stability analysis method.