Abstract: The process of soft-punch hydro-forming was used to form some workpieces. However, it has not been completely understood until now. In this paper, based on some primary experiments, in which cups have been tried under different working conditions with the soft-punch hydro-forming process, systematical know-how about why the LDR of a metal sheet is different, how working conditions influence qualities of a work-piece, and how the deformation takes place has been achieved when simulations are employed. All these results claim that the cup depth heavily weighs on the cup wall thinning rate, and a satisfied complex part can be achieved when the contacting time between the sheet and the female die is under our control well by a movable slider, which is fixed as the bottom of the female die.

Key words: Soft-punch hydro-forming, Sheet metal forming, Metal sheet forming simulation