Forming Limit Diagram using FEA

Abstract: Sheet metal forming is the process of converting flat sheet of metal into a part of desired shape without fracture or excessive localized thinning and widely used in aerospace, automotive, appliances industry. In sheet metal forming failure can be predicted by Forming Limit Diagram (FLD). FLD offers a convenient and useful tool in sheet products manufacturing analysis. They show the critical combinations of major strain and minor strain in the sheet surface at the onset of necking and are also used during the design stage of any new sheet metal component for tooling shape for optimizing process variables of new product development. In this research, the effect of n-value (strain hardening exponent), punch velocity & sheet thickness on FLD were studied using FE based HYPERFORM software. As new market requirements are becoming more persistence through introduction of new technologies for improvements in performance trends, these FEM based software simulation is becoming more affordable & reliable as they reduce lead time & cost. It also improves productivity & quality. A typical industrial component was chosen for analysis. The results demonstrate that FLD0 increases with increasing n-value & sheet thickness but for punch velocity more iteration are required