Forming-limit diagram numerical predictions: yield criteria studies

摘要

In this work, it is shown the numerical formulation for prediction of the right-hand side of forming limit diagram (FLD). Five different yield criterias were used: Von Mises', Hill's (1948), Hill's (1979), Logan and Hosford's and Hill's (1993). Two new explicit equations for the equilibrium conditions using Von Mises and Hill's (1948) yield criteria are presented. The results were compared against theoretical and experimental data present in the literature with good agreement. The materials used in the comparison were the 2036-T4 aluminium and the AK, IF e EEP steels. It was observed that the predicted FLD was strongly influenced by the type of yield criterion used in the analysis. The best agreement between the predicted curves and the experimental data for each material was obtained from different criteria. The best result for the AK steel was achieved from the Logan and Hosford's criterion. The 2036-T4 aluminium was better represented when the Hill's (1993) criterion was used. The IF and EEP steels were well represented by results based on either Hill's (1979) or Logan and Hosford's criterion.