Author : A C Sekhara Reddy, S.Rajesham and P. Ravinder Reddy

At the outset, the number of stages in design of multistage deep drawing process must be evaluated in order to optimize the process conditions. The estimation of number of steps involved in accomplishment of the required shape of the component mainly depends upon the limiting drawing ratio (LDR). In deed, LDR is an essential design component to be familiarized by process engineers in minimization of forming steps for multistage deep drawing process in which the forming of finished component cannot be achieved in single stage deep drawing process. LDR is defined as the ratio of maximum diameter of the blank that can be successfully drawn under the given punch diameter. In essence, it establishes the maximum size of the blank that can be successfully drawn for the given punch diameter. The determination of LDR by traditional methods is a lengthy, costly. In contrast to that, the present method described here in this paper is often called as “rapid determination of LDR based on characteristic limit load”. This method of LDR determination consumes less time. It is also fast and essentially needs only three sizes of test samples under the given process conditions. The experimental investigation of rapid determination of LDR had been performed on an automotive aluminum alloy sheet AA6111 and the procedure is based on characteristic limit load. The results are in good agreement with the traditional methods that are already established in industry.

Keywords: Deep drawing, Rapid FLD, Normal anisotropy, Planar anisotropy, plastic strain ratio. Wrinkling

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.2 (April- 2014)