Prediction of Sheet Drawing Characteristics with Square Drawbead Elements Using Response Surface Methodology

Drawbeads are often used in the sheet metal forming processes to provide a better control of the material flow into the die cavity. The drawbead restraint force (DBRF) and the exit thickness are two important sheet drawing characteristics to be determined for the selection and installation of the drawbead elements. This study presents the effects of drawbead geometry and sheet material on drawbead restraining force and thinning. Mathematical correlation between the drawbead geometry, sheet material and drawing characteristics was investigated by using Response Surface Methodology (RSM), which is a global approximation method ideally suited for solving highly nonlinear optimization problems. The proposed response surface model for DBRF and thinning showed a good correlation with the experimental data available in the literature. RSM could be considered as an alternative and practical technique to evaluate the sheet drawing characteristics. The method can also be applied to other sheet metal forming issue.