A new asymmetric yield criterion based on Yld 2000-2d under both associated and non-associated flow rules: Modeling and validation

A new asymmetric yield criterion is developed by introducing asymmetrical parameters into Yld 2000-2d. It has been proved that the convexity of the proposed yield criterion is guaranteed. A 'sum' form of yield functions is used to increase the flexibility of the yield criterion. One of the advantages of the developed yield criterion is that the convexity of yield criterion is independent of the anisotropic parameters. Besides, the proposed yield criterion not only possesses the inherent characteristics of Yld 2000-2d under tensile stress states but also can be used to predict material's strength differential (SD) effect. By applying the constructed yield criterion to FCC and HCP materials, the accuracy and flexibility of the proposed yield criterion are verified. The results show that both the 11 and 16 parameters yield criteria for non-associated and associated flows, respectively, can accurately capture the SD effects of these materials. In addition, the proposed yield criterion not only can predict the tension-compression asymmetry along the rolling and transverse directions but also can accurately predict the SD effect along the diagonal direction.