Theoretical and experimental sheet metal failure evaluation

Paper in proceeding, 2007

In the present paper some results from an ongoing study on the prediction of necking and fracture in connection to sheet metal forming are presented. The materials used in this study do all show a distinct necking behavior before fracture. In fact, the formation of an incipient neck is here used to define the limit strains. Three groups of methods for defining limit strains are used in this study. These are: experimental methods, theoretical/analytical methods, and Finite Element methods. The various methods are briefly described in the report. Unfortunately, there is a considerable scatter in results between the various groups of methods, and also within the separate groups. These discrepancies are analyzed, and explanations for them are given where possible