Prediction of forming limit diagrams for deep drawing

Different theoretical approaches to determination of the forming limit diagrams at necking and rupture while considering the influence of the constitutive law, surface defects and evolution of volume damage are presented. The use of steels of increasing strength and decreasing thickness is associated with different forming problems such as spring back, surface deflections, low forming limit. The optimization in the use of these materials through careful modelling of sheet metal forming is discussed.