Modeling of drawbead restraining force in sheet metal forming

Drawbeads are used as control mechanism regulated the flow rate at certain locations of the sheet to minimize or prevent defects such as tearing, wrinkling and springback that occur on sheet during a sheet metal forming process. In this study, drawbead restraining force was measured for the sheet metal through blankholder and lower die with a round drawbead with various penetration. This experimental data were used and the mathematical model calculated drawbead restraining force as a function of bead penetration was developed. Comparison of the results of mathematical model with the corresponding experimental results and PAM-STAMP model was showed in excellent agreement