In order to find the effect of frictional characteristics,lubricant viscosity,tool geometry,and forming speed on the sheet metal forming,a friction tester was designed and manufactured.Friction tests were performed using drawing oils,various tool radii and forming speeds for aluminum alloy sheets,galvanized steels sheets and cold rolled steel sheets.From the experimental observation,the mathematical friction model considering lubricant viscosity,sheet surface roughness and hardness,punch corner radii,and punch speed is developed.By comparing the punch load found by FEM using the proposed friction model with that of experimental measurement when the steel sheets are formed in 2-D geometry in dry and lubricating conditions,the validity and accuracy of the mathematical friction model are demonstrated.
展开▼
