Simulation of the hydroforming process using a new orthotropic yield criterion

The paper presents a new anisotropic yield criterion and its implementation in a finite-element code. The yield criterion is an extension of the formulation proposed by Barlat and Lian in 1989. In order to obtain a better representation of the plastic behaviour of the orthotropic sheet metals, some additional coefficients have been included in the expression of the equivalent stress. The finite-element programme has been used for simulating a hydroforming process. The numerical results have been compared with data published in the literature. (C) 2004 Published by Elsevier B.V.