A new approach, the "Facet" method, is proposed to implement the anisotropic plastic behaviour of textured materials in finite element models for the simulation of metal forming. It is based on an analytical expression of plastic potentials in strain rate space and/or stress space. The method has been designed to be used in combination with a multilevel model for the plastic deformation of the polycrystalline material. The parameters of the expressions for the plastic potentials are identified by fitting to the predictions of the multilevel models instead of being fitted to the results of mechanical tests. The new formulation has the advantage that it automatically ensures convexity of the anisotropic yield loci. Moreover, it is more flexible than the previous method, and can in principle be used with more advanced multilevel models than the Taylor theory. In contrast to most existing methods, the new method can also be applied to materials with a stress differential effect. For now anisotropic equipotential surfaces in strain rate space will be shown. They are obtained by the Facet method combined with the Taylor theory, for a model texture and for three industrial materials, and will be compared with results directly obtained from the Taylor theory, without passing through an analytical model.
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