Numerical optimisation of a two-layered X-shape hydroforming joint by finite element and response surface methodology

Tube hydroforming is an innovative metal forming Process by which many near net-shape industrial parts can be manufactured. Two-layer hydroformed parts, produced by this process, are appropriate for application in Oil and gas industry as well as aerospace. In this paper, the X-shape multi layer tube hydroforming process is simulated using the finite element method. A double-layer tube, outer layer brass and inner layer copper, was used initially to produce a composite hydroformed part. Different thickness setting for initial tube was suggested by design of experiment methodology. The suggested initial parts were later modeled and analyzed. Finally, response surface methodology (RSM) was adopted to plot results. Design parameters like, Weight, protrusion height, thickness reduction in protrusion region and thickness increase of produced part in central region were important to be controlled during production. Therefore, the initial thickness of layers was optimized in order to reach the best predefined product. All response surfaces were considered simultaneously during optimization to find the best optimum part possible which fulfilled all desired conditions. In order to verify the approximation, an initial tube with the optimum geometry was analyzed using FEM. At the end, both analyzed and predicted results were compared.

Keywords:

Tube Hydroforming-Deformation-Multi layered-FEA-Simulation