Mechanism of Wrinkling in Deep Drawing of Sheet Metals : 1st Report, Theory of Flat Die Drawing

Abstract

A theoretical investigation of wrinkles arising in flange part during deep drawing of circular sheet metals is reported. In this case, we assumed the formula of wrinkles by a set of experiments on various drawing conditions and as a buckling problem of circular plate, the energy method wae used. The following items were found : For elastic and plastic wrinkling, the effect of blank holding force, rigidity of blank holding system, constraint at the part of draw-in (several die contour), drawing ratio, lubricant, material constants and thickness of sheet blank. And the critical condition of wrinkles was also discussed.