Optimization method of spindle speed with the consideration of chatter and forced vibration for five-axis flank milling

Spindle speed optimization is important for the machining industry to improve the material removal rate (MRR). However, low spindle speeds are always used to avoid inaccuracy caused by the chatter and forced vibration. Especially for the five-axis flank milling, the selection of spindle speeds is conservative since the complexity of the tool-workpiece engagement (TWE) and the corresponding dynamics. This paper presents a spindle speed optimization method to improve MRR with the consideration of chatter and forced vibration for five-axis flank milling. Chatter and forced vibration models of five-axis flank milling are developed based on the general cutting dynamics model. The root-mean-square (RMS) values of the forced vibration displacement are employed to evaluate the surface quality. The relationship between the stable spindle speed and the forced vibration reveals that the surface quality is positively associated with the spindle speed in some specific ranges, and MRR is improved by increasing the spindle speed in those ranges without the risk of increasing inaccuracy. The simulation results and experimental work show that the proposed method can be used to optimize spindle speeds for improving MRR without inducing chatter and aggressive forced vibration.