Abstract
After the sheet metal is plastically deformed to the required product shape in the stamping process, there is an elastic recovery of the sheet metal, known as spring back. This results in dimensional variation of the stamped part. One characteristic of spring back is sidewall curl. Side-wall curl is a result of residual stresses through the thickness of the sheet metal produced by non-uniform deformation. This effect is most commonly observed in deep drawn high strength sheet metal rails which are used as structural parts in automotive BIW (body in white). The primary objective of the study is to evaluate the impact of various draw bead shapes on side-wall curl with computational analysis. A simple hat shaped channel section is considered for the study. The analysis is carried on HSLA (High strength low alloy) material. Standard draw bead geometries such as round, rectangular and trapezoidal were modified to check the impact on side-wall curl. It is observed from the study that; side-wall curl reduces with the reduction in stress gradient and uniform stress distribution. In the evaluation, it is found that trapezoidal draw bead shape has a better impact on side-wall curl radius reduction, compared with other draw bead shapes.