Anisotropic Yield Criteria

Abstract

The most widely used isotropic yield criteria are defined in terms of the principal values of the stress deviator. In this paper, it is demonstrated that these yield criteria are expressible as polynomials in terms of the second and third invariants of the stress deviator. Using these new mathematical results, new, simple and explicit expression of Yld91 and Karafillis and Boyce [1] orthotropic yield criteria in terms of stress components are obtained. Moreover, it is shown that for orthotropic BCC materials, Yld 91and Karafillis and Boyce [1] criteria are particular forms of Cazacu and Barlat [2] orthotropic yield criterion.