Analysis of key parameters in sheet hydroforming combined with stretching forming and deep drawing

Sheet hydroforming has proven to be an effective method for manufacturing complicated parts. To explore sheet deformation under complex strain conditions, the forming process of a conical cup was studied on the basis of the proposed hydromechanical deep drawing with uniform pressure on to the blank. The failure types including fracture and wrinkling aout using the different roughness of the punch surface in local areas. The forming parocess of the conical cup was explored using pure aluminium and soft steel. Effects of the key process parameters including the punch surface roughness and the pressure variation on the finally formed parts were investigated in both experiment and simulation. It was shown that the results from the simulation were in reasonable agreement with those from the experiment.