“…In this case, the modulation in chip thickness caused by a nonuniform pitch can reduce the vibration under disturbance. Aiming at predicting the stability of milling process with VPC, frequency-domain model [12,13], the Cluster Treatment of Characteristic Roots [14], unified SDM [15], improved FDM [16,17], and improved SDM [18] have been proposed successively. Furthermore, Sims et al [19], Sims [20], Dombovari and Stepan [21], and Jin et al [22,23] proposed efficient methods to predict the stability for VPC and variable helix cutter, while Yusoff and Sims [24] optimized the geometry of variable helix tool to suppress regenerative chatter.…”