A study of surface deflection in pressed automobile panels

There is no perfect evaluation criterion presently that can satisfy the needs of the engineering and the research on the surface deflection of automobile outer panels. A convenient 2D and 3D evaluation criterion that can quantitatively measure the magnitude and the location of surface deflection is developed mathematically. The surface deflection is shown by comparing the curvature variations between the pressed panel and the punch. The evaluation criterions tested by example are correct. The surface deflection is investigated through the experiment of the double-curved shallow shell drawing parts. The mechanism of surface deflection and the effects of forming conditions on surface deflection are analyzed. And the influence law of forming conditions on surface deflection is achieved, such as binder force, curvature radius (arc height of punch), sheet thickness, materials property and draw-beads.