Experimental and numerical analyses of sheet hydroforming process for production of an automobile body part

An approach for substituting conventional manufacturing method of a three pieces shell fender by one piece has been proposed. This approach is based on sheet hydroforming process, which has many advantages over conventional stamping processes. For production of shell fender by sheet hydroforming, two possible manufacturing procedures have been evaluated numerically, namely; pure stretching and draw-in. In addition, results of both finite element simulations and experiments on small size specimens show superiority of draw-in procedure. The advantage of draw-in over pure stretching procedure has been explained using thickness variation measurements. Furthermore, the draw-in procedure of shell fender has been optimized with respect to initial blank size, fluid pressure and required tools using an explicit commercial forward finite element program. Finally, the effects of sheet material and fluid pressure on the required deformation force in laboratory scale have also been evaluated.