A GEOMETRICALLY COMPREHENSIVE APPROACH TO MODELING DYNAMIC CUTTING FORCES IN TURNING: APPLICATION TO REGENERATIVE CHATTER

Present chatter models in turning lack physical insight because they do not model the process in a geometrically rigorous manner. Many of the models are linear and produce unrealistic, unbounded vibration amplitude growth after the onset of chatter. Those that are nonlinear are typically reverse engineered in order to predict bounded vibration. The current approach models the forces in machining due to chip formation, plowing, and interference between the flank of the cutting tool and the machined workpiece surface in a geometrically comprehensive fashion. Additionally the effects of strain, strain rate and temperature oil the chip formation process are captured. In doing so, accurate predictions can be made for both the occurrence of chatter and its vibration amplitude growth over time. The proposed model is validated with machining experiments on a compliant workpiece to explore the effect of tool nose radius on chatter.