Friction in Orthogonal Cutting Finite Elements Models with Large Negative Rake Angle

In this paper, orthogonal cutting finite elements models are built for the investigation of the impact of large negative rake angles on the friction coefficient in the tool-chip interface in machining. The simulation results give an insight on the mechanism of chip formation in processes with large negative active rake angle, such as machining with chamfered tools, grinding and micromachining. For the present analysis, cutting conditions resembling the qualitative and quantitative characteristics of the aforementioned processes were selected. More specifically, tool rake angles varying from -10o to -55o and Coulomb friction with constant friction coefficient were considered. The results indicate that friction coefficient is greatly affected by the negative tool rake angle, exhibiting values well above 1 for the high extreme of the examined rake angle spectrum.