Multistability in milling dynamics with tool runout
摘要
Traditional models used to study regenerative machine tool chatter often ignore the radial runout of multi-edge milling cutters and its influence on dynamic stability. This runout induces asymmetric forced vibrations within each spindle revolution, which can lead to irregular variations in the cutter-workpiece engagement and in the delay patterns of the cutting process. The actual dynamical system involves multiple time delays, fly-overs, and nonlinearities, which pose significant challenges for standard numerical solvers. In this study, a path-following continuation technique is employed to explore new periodic motions that emerge when runout is considered. The results reveal that the system’s behavior is more complex than previously thought, with multiple stable and unstable solutions appearing within a specific range of technological parameters. Theoretical findings predicted by the improved model were successfully validated experimentally using a workpiece with a single dominant vibration mode. This work demonstrates the existence of isolated solution branches and bistability under realistic operating conditions.