Investigation into sheet hydroforming based on hydromechanical deep drawing with uniform pressure on the blank

Sheet hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as a higher forming limitation, good quality of the formed parts, the capability of forming complicated parts, etc. Based on the proposed hydromechanical deep drawing (HDD) with uniform pressure on the blank, some characteristics of sheet hydroforming, including the drawing ratio improvement, the quality of the formed parts, the thickness distributions of the formed parts and the process window, are investigated in detail. The effect of the process parameters on the features and ways to improve the sheet formability are discussed both in experiment and simulation. With consideration of the forming limit diagram (FLD), the forming process was studied in simulation. The results from a simulation were in reasonable agreement with those from an experiment.