Recent Advances in Process Design for Sheet and Tube Hydroforming

The paper is concentrated on the last developments related to process design for sheet and tube hydroforming. The paper first analysis the ways to properly account flow movements and pressure drops occurring in sheet and tube hydroforming that can interact with sheet or tube deformation during hydroforming described with a flow-structural approach, based on an ALE approach accounting well the structural interactions. Then different optimization strategies for process parameters are presented on the basis of cost functions associated to final geometry of sheet or tubular components, based on gradient approaches as well as stochastic ones, depending on the number of parameters and on the sensitivity of parameters relatively to the response functions. Finally an integrated design approach based on control of processes is described combining optimization and continuous adjustment of process parameters to get the required parts accounting the machine tool limits and the material ones. Different applications are given related to typical components that are used in automotive industry.