Finite thermoplasticity with phase changes based on isomorphisms

The phase changes which occur under the heat treatment in different materials lead to some additional deformations and change of mechanical properties. They can be influenced by applied loadings. In this paper a model of finite thermoplasticity with phase changes based on the concept of isomorphism of elastic ranges is presented as an extension of the thermoplasticity theory developed by Bertram. We do not use the concept of the decomposition of strains, although it can be incorporated in our framework. Restrictions due to the second law of thermodynamics are discussed. Mass fractions are used as internal variables to describe the evolution of phases. Our model is presented on a rather general level as a frame which can be applied to different materials.