Alternative Stamping Technologies for Automotive Panels

In the field of new stamping technologies, hydroforming represents one of the most attractive solution both to reach a better quality and reduce lead-times. This paper presents a study that is being carried out to assess an optimal hydroforming process for production of automotive panels. The major economical advantages are due to the need of only one dedicated shape-defining tool, this leads also to a more flexible production system.

The research starts from the analysis of two different process arrangements: hydro-punch versus negative or positive die. Their numerical simulations (performed by LS-DYNA3D) are used to define the values of control factors (maximum pressure, blankholder force) and to highlight, in terms of shape and strain field accordance, the pros and cons of each solution. To assess the better arrangement an economical evaluation is carried out using a decision making approach. The discussion is based on press shop experience related to three different components: an exterior panel of a bus, a detail of bus luggage van and a bus roof.