Thermomechanical representation of the stored energy during plastic deformation

In the theory of metal plasticity, the energy storage phenomena during plastic work have been intensively debated in recent decades. Experimental results show that there is a significant amount of energy storage, which depends strongly on the process history. However, modeling of this important phenomenon is often treated in a rough manner by introducing a heat source into the heat conduction equation. In contrast to such an approach, the use of a thermomechanical framework allows for the coupling of thermal and mechanical phenomena into a comprehensive theory. Different approaches for the additional stored energy function are proposed and discussed in the context of a finite strain theory. By using the suggested approach, the observed thermomechanical coupling phenomena of Chrysochoos et al. on aluminum 2024 and a carbon steel XC 38 are well representable.