Shape and Thickness Optimization of an Aeronautical Structure Manufactured Using Age Creep Forming Process

We present a numerical method to optimize the age creep process for the manufacturing of spatial structures. In particular, we study the forming of Ariane 5 bulkheads. They are obtained by assembling eight segments which have to be a portion of sphere. Each one is formed by blowing a sheet against a die following a predetermined thermo-mechanical cycle (temperature and pressure). To take into account viscoplastic strains we have identified a non-isothermal Chaboche-Lemaitre model.