The flow of sheet metal over a drawbead involves three-dimensional deformation, especially near and at the drawbead ends. The strain paths of a number of points of interest in the sheet had previously been analyzed using FEM. A modified M-K analysis was used to generate forming limit curves for a number of the deformation conditions for a typical automotive steel. For the drawbead geometry selected and penetration specified, the strains experienced by the sheet are shown to remain below the respective forming limit curves. This indicates that failure by necking is not expected as the sheet flows over the drawbead. However, wrinkling may occur due to a compressive stress state near the drawbead end.
| Number of Pages : | 6 |
| Published : | 11/01/1998 |
