Effect of the Draw-bead and Blanking Holding Force on the Sheet Metal Forming Process

Abstract

This paper is concerned with the quantitative effect of the draw-bead and the blank holding force on the sheet metal formed part. The draw-bead analysis is newly carried out to provide the restraints force of the draw-bead for finite element analysis of sheet metal forming. The draw-bead analysis has been carried out in the two steps: first, the draw forming analysis has been carried out; and secondly, the drawing analysis has been performed. The results provide the restraint force of the draw-bead as well as the displacement in the region of the draw-bead, which is utilized as boundary conditions in finite element analysis of sheet metal forming. And then, the sheet metal forming analysis is carried out to investigate the effect of the draw-bead on the quality of forming. Numerical results demonstrate that the forming history becomes totally different depending on the restraining method such that the forming is not successful with the use of only the blank-holding force while it is successful with the use of the draw-bead. It is also noted from the comparison of the analysis result with the experimental one that the present analysis method is effective in sheet metal forming simulation.