Finite strain analysis of simple shear using recent anisotropic yield criteria

The finite strain response of a rectangular block subjected to constrained simple shearing deformations is considered in order to evaluate the predict ive capability of some recently proposed anisotropic yield functions. It is shown that, in the presence of plane anisotropy, the prediction of realist ic second order normal stresses cannot be expected since every different in itial orientation of the material axes relative to the loading axes results in a different response due to the rotation of the material axes with shea r. Parametric studies are performed in order to determine possible limits o n the material constants so that the predicted normal stresses remain secon d order with respect to the shear stress itself. Our numerical results indi cate that, in particular, the commonly employed range of one parameter asso ciated with grain related anisotropy renders results which no longer imply predicting a proper second order effect but rather introduces errors of the first order. The results suggest that the modelling of anisotropy with suc h phenomenological anisotropic yield functions should be limited to near-qu adratic yield surfaces for applications involving stress states outside the biaxial tensile stress range. (C) 1999 Elsevier Science Ltd. All rights re served.