A Study of Milling Surface Quality during Period-2 Bifurcations

This paper provides time domain simulation and experimental results for surface location error and surface roughness when machining under both stable (forced vibration) and unstable (period-2 bifurcation) conditions. It is shown that the surface location error follows similar trends observed for forced vibration, so zero or low error conditions may be selected even for period-2 bifurcation behavior. The surface roughness for the period-2 instability, on the other hand, is always larger than for stable conditions because the surface is defined by every other tooth passage and the apparent feed per tooth is subsequently increased. Good agreement is observed between simulation and experiment for stability, surface location error, and surface roughness results.