Advances in predicting damage evolution and fracture occurrence in metal forming operations

The paper reports the latest trends in prediction of damage evolution and fracture during metal forming processes. Both uncoupled (e.g. the Oyane law) and coupled (e.g. Continuum Damage Mechanics-based laws) models are outlined and applications of the two approaches are presented. In particular, three application cases, which may be characterized by fracture events, are discussed: (i) a cold forging sequence, where a fracture criterion is utilized in combination with a damage accumulation law; (ii) a hot stamping operation conducted on high strength steel sheets, where the Continuum Damage Mechanics approach is used instead of the conventional one based on Forming Limit Curves; (iii) a hot rolling operation, where the Lemaitre law is modified to take into account the influence of the temperature and initial microstructure.