Blank-holding effect on the hole-flanging process of sheet aluminum alloy

The effect of blank-holding on the hole-flanging process was investigated using numerical and experimental analysis. Hole-flanging was performed with fixed blank-holder, without blank-holder, with constant blank-holding force and with progressive blank-holding force. Progressive blank-holding force was supplied by springs or preloaded springs. An elasto-plastic finite element model was used to predict the forming kinematics, the punch load and the final shape. A commercial sheet of aluminium alloy with a thickness of 2 mm was selected for this work. Experiments were conducted in order to verify the reliability of the developed elasto-plastic finite element model. The experimental results demonstrated that the finite element model can be used to determine the suitable blank-holding condition for each case.