Abstract: To avoid chatter in circular milling, the dynamics of circular milling is modeled to include the regenerative effect, and the corresponding average directional force coefficients are derived. When the fact that the rotation speed of the spindle is much larger than the angular speed of the feedrate, the same average directional force coefficients are obtained for the circular milling with that of the linear milling by approximation. Therefore, the analytical chatter model for the linear milling can be applied to the circular milling; the precondition is that the maximal radial engagement angle instead of the nominal radial engagement angle should be used. The expressions of the maximal radial engagement angle for circular milling with both uniform and non-uniform radial depth of cut are derived by the geometrical relationship between the cutter and the workpiece. The dynamic simulation module is developed for circular milling based on dynamic modeling, and the simulation results are verified by cutting experimental tests. As a result, an effective approach can be provided for the determination of cutting conditions of circular milling.

Key words: Chatter stability lobes, Circular milling, Cutting conditions optimization, Dynamic simulation