Abstract: An improved sheet hydroforming process with a movable die is proposed and investigated by elastoplastic FEM. The effects of varied process parameters on the deformation of the sheet blanks were investigated. The effects of the movable die on the FLD were also analyzed. Using a movable die may increase the forming limit of the blank and improve the forming performance. Moreover, the drawing ratio of the blank may be increased by changing the process conditions such as blank holder force and the counterforce of the movable die on the blank.

Key words: Hydroforming, Sheet metal forming, Movable die