Sheet Metal Formability-Comparisons Between Computer Modeling and Production Case Histories

Mathematical modeling of sheet metal forming is now a reality for designing of automotive stampings. The input of one such mathematical model includes part geometry, forming mode, material properties, forming speed, and coefficients of friction. The output includes strain distributions and forming severity derived from the Forming Limit Diagram. The mathematical model identifies critical forming zones during the initial part design stage and allows what-if scenarios to be investigated before the final design is committed to soft or hard tooling. The designer can evaluate various design versus production options for reducing the severity of the stamping. This paper illustrates potential uses for this design tool with two design case histories - 1) a drawn corner of an inner door stamping and 2) a stretch zone for an outer door handle pocket.