Effects of Sheet Thickness on the Coefficient of Friction Determined by the Draw Bead Simulator (DBS) Test

This study addresses the effects of sheet metal thickness on the frictional forces which develop when a strip of sheet metal is pulled through a draw bead configuration. This situation is represented by the draw bead simulator (DBS) test. Sheet steels of various thicknesses in the range 0.5-1.5 mm (0.02-0.06 inches) were used for the analysis. Generally, the coefficient of friction decreases with increasing sheet thickness when the conventional expression for coefficient of friction (μ) is used. A correction factor is proposed which normalizes the μ-value over a range of thicknesses. Also, suggested uses, limitations and improvements for the device are made.