Analytical evaluation of plasticity models for anisotropic materials with experimental validation

The plastic behavior of a material can be represented by plasticity models. The ability of plasticity models to represent material behavior depends on their mathematical form, the assumptions they hold, and the sensitivity of the input parameters. Plasticity models are of great importance, especially in finite element analysis. While the mathematical forms of plasticity models are implemented in finite element analysis software, some coding-related inaccuracies may occur. Therefore, the capacity of the plasticity model to represent the plastic behavior of the material can be revealed more accurately by examining it analytically. After this verification, the choice of the plasticity model to be used in the finite element analysis can be realized with more accuracy and less time loss. In this direction, in this study, the capacity of plasticity models, which are frequently used today, to model the plastic behavior of anisotropic materials was evaluated. For this purpose, Hill48, Barlat89, Hu2003 and Poly6 plasticity models were analyzed analytically and TBF1050 3rd generation advanced high strength steel and 5XXX series aluminum alloy were used as materials. The predictive capacities of the plasticity models were evaluated with the yield locus and angular variations of anisotropy coefficient and yield stress ratios. As a result, it has been revealed that polynomial-based models can model the plasticity behavior of the material more accurately for both material groups.