Investigation and comparative analysis of plastic instability criteria: Application to forming limit diagrams

摘要: The prediction of forming limit diagrams (FLDs) is significant interest to the sheet metal industry. Although a large variety plastic instability criteria have been developed during previous decades, there still lack comparison their respective theoretical bases. aim this paper present formulations representative selection diffuse necking and strain localization based on maximum force principle, Marciniak–Kuczynski method bifurcation approach. foundations underlying assumptions for each criterion are specified prior application several materials determine associated FLDs. capability predict formability thin sheets discussed classification some attempted according order occurrence in terms prediction.