Stability Analysis of Interrupted Cutting With Finite Time in the Cut

The stability of interrupted cutting is examined for the case in which the tool is in contact with the work piece for a small, but finite, fraction of the tooth-passing period. A model of a single degree-of-freedom tool excited by intermittent, regenerative cutting forces is analyzed. The equations are transformed into a discrete model by use of the exact analytical solution when the tool is free of the work piece, and by an approximate analytical solution (the method of weighted residuals) when the tool is in the cut. Stable combinations of spindle speed and axial depth of cut are found. These results confirm and refine predictions of additional stability regions made by Davies et al. (1999a, 2000) based on the approximation of infinitesimal time in the cut.