Modeling the joint of tool-work interface friction and work material bulk deformation in metalworking processes

Abstract

Asperity interaction models have been developed using the slipline field theory to explain the role of tool surface roughness, lubrication condition, and apparent contact pressure on the tool-work interface frictional boundary condition in metalworking processes. In this paper, consideration is given to how the slipline fields representing asperity interactions can be joined to the slipline field representing the bulk deformation for the process considered. All the possible contact conditions at which the ratios of the real and apparent contact are less than or equal to one are considered. The joint of tool-work interface friction and work material bulk deformation is thus modelled by the combined slipline field for the interface friction and the bulk deformation. Tests for overstressing of critical corners in the combined slipline field are carried out using Hill's theorem on the maximum intensity of stress singularities. The influences of tool surface roughness, lubrication condition, and apparent contact pressure on tool-work interface friction and work material bulk deformation are shown using the combined field model. © 1993.