Development of Uncoupled Anisotropic Ductile Fracture Criteria

Two mainstreams of transformation methods from isotropic fracture criteria to anisotropic ones are to replace the Von Mises yield function with other yield function and linear transformation of strain or stress tensor. Several typical anisotropic criteria such as the transformation methods of Park, Luo, Lou and Yoon, Jia and Bai and a new transformation method are analyzed and discussed from the aspects of required experimental data, material constant amounts, stress state range, average predictive error (Erravg), etc. The fitting results demonstrate that the prediction accuracy of the methods of Luo, Lou and Yoon, Jia and Bai and the new method are better than that of the isotropic criteria from the Erravg aspect based on the experimental results of DP590. In addition, the new transformation method linearly transforms both stress and strain tensor without increasing too many parameters.