Thermodynamically consistent modeling of yield surface distortion

From a macroscopic point of view, the deformation of most metals results in an evolution of the symmetry groups characterizing the isotropy of the considered materials. With respect to plastic deformation for instance, the shape of the macroscopic yield surface evolves during deformation. In the present paper, a novel constitutive framework capturing this evolution is proposed. This framework is based on the fundamentals of thermodynamics. Furthermore, it also shows a variational structure such that all state variables follow jointly from minimizing an incrementally defined energy functional. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)