Materials Science Forum, Vol.455-456, 732-736, 2004
Springback evaluation with several phenomenological yield criteria
In the last decades, several orthotropic phenomenological yield criteria were proposed to accurately describe the anisotropic behaviour of the rolled metallic sheets that are widely used in the production of sheet metal formed parts. In this work, the authors evoke the implementation of several yield criteria in the implicit finite element code DD3IMP, namely the Hill 1948 , the Cazacu & Barlat 2001  and the isotropic Drucker's yield criterion mixed with a linear transformation . The Numisheet'2002 benchmark "Unconstrained Cylindrical Bending" was selected to evaluate the influence of the yield criteria on the springback evaluation. A 6111-T4 aluminium alloy was used. Its mechanical characterization was performed by Alcoa . The results show that only the Cazacu and Barlat 2001 yield criterion fits very accurately both the uniaxial tensile yield stresses and the r-values. All the other yield criteria fits rather well the experimental r-values. Concerning the influence of the yield criteria on springback, only a minor influence was found. However, the results obtained from the Cazacu and Barlat 2001 yield criterion are clearly the closest to the experimental ones .
Keywords:sheet metal forming;phenomenological yield criteria;plasticity;anisotropy;constitutive models;DD3IMP