Best of Both Metals in Body Parts Light Weight Concepts for a Hood

New ways for constructing hoods have been explored. They have become feasible because of the advent of new processing techniques such as tailor-made blanks and hydroforming and by using new materials, including IF rephosphorized High Strength Steel, Aluminum Body Sheet and Hylite sandwich material. Three concepts were selected for evaluation: a hydroformed tube inner part, an aluminum closed box construction and a foam filled sandwich with Hylite outer part. A comparison of static and dynamic dent resistance of the different materials leads to the required thickness of the outer part depending on the selected material. A simplified finite element model has been used to optimize the geometry of the inner panel. CAD-designs have been used to evaluate functional properties by FEM-calculation and to evaluate if the inner part can be formed by a drawing operation. Finally a cost evaluation was made by means of the MIT cost model.