A finite-element simulation of asperity flattening in metal forming

A three-wavelength finite-element model for asperity flattening has been developed based on an analysis of measurement data for steel sheet surface. The simulation of asperity-flattening procedure indicates a non-uniform contact pressure distribution and a large stress concentration appearing on the contact surface. Evolution of contact ratio and surface roughness are investigated by a simulation under various friction conditions and comparison with other models is made. The effect of relative sliding between the workpiece and tool and friction factor is discussed. An equation of the contact area ratio as a function of load, friction and sliding velocity is also presented based on the simulation results. The results are in reasonable agreement with experimental measurements.