On a thermodynamical consistent constitutive law based on the concept of internal variables

A multiaxial constitutive law describing the behaviour of polycrystalline ice in a phenomenological way will be introduced. Internal variables represent the hardening and softening of the material and also a modified inelastic work. The equations are implemented in a thermodynamical frame.To derive the unknown functions and parameters a strategy is developed, facilitating the fitting in a simple and fast manner.Finally, the comparison between computations and experiments shows a good agreement.