Tube Hydroforming Process Optimal Design by Improved Dynamic Programming 2011-01-0236

Due to its capability to make tubular components with high structural rigidity and low mass, tube hydroforming (THF) is an important manufacturing process to make lightweight automotive structural components, such as engine cradles, crank shafts, seat frames, roof bow and instrument panel beam etc. In order to integrate more functions, tube hydroformed components (THC) usually have complex geometry and are formed from a straight tube usually by three stages, which are programmable CNC bending, pre-crush and hydroforming. Since the complexity of component geometry, failures, such as fracture and buckling, could happen simultaneously at different spots. Tube bending and hydroforming process are designed to eliminate multiple failures and thus the THF development is tedious and time consuming. In this study, a multiobjective dynamic programming method is developed to optimize the THF process and demonstrated on an automotive component.