DefinePK

Abstract

In sheet metal forming operations, the most deleterious defect are wrinkling, tearing, necking and springback. Wrinkling of cups drawing was simulated using the finite element method (FEM). The fem code Auto form was used in numerical analysis. Wrinkling phenomenon is affected by the mechanical properties of the blank sheet material, contact conditions, blank holder force (BHF) and the geometry of the punch and dies. The wrinkling prediction is difficult to perform due to the highly sensitivity of the parameters. The effect of parameters of BHF and friction coefficient in the cup drawing process are studied. The small variations of the parameters can result in widely different wrinkling behaviors. The objectives of this paper are to investigate the effects of lubrication and blank holder force on a dome wrinkling behavior. The experiment was conducted in lubricated condition, without lubrication and BHF variations of 1, 3, 5 and 8 kN. Two different blank sheets of Aluminum and Steel have been selected. The result shows that the dome wrinkling generation was influenced by blank holder force, while the lubrication did not give different result.