Advanced Models for the Prediction of Forming Limit Curves

Abstract

During the forming of flat sheet metal into a more complex shape, a number of plastic instabilities may occur subsequently. A `plastic instability' occurs when the zone of plastic deformation is suddenly confined to a smaller zone. The first plastic instability which usually occurs in forming processes is the onset of diffuse necking, in which plastic deformation is confined to a smaller zone, but with typical dimensions that are still in the order of magnitude of the part's dimensions.