Thermal Stresses in Metallic Materials Due to Extreme Loading Conditions

The role of thermal stresses, understood as stresses introduced by a uniform or nonuniform temperature change in a body which is somehow constrained against expansion or contraction, in metallic materials due to extreme loading conditions is under consideration. The thermomechanical couplings (thermal expansion and thermal plastic softening phenomena) have a fundamental impact on damage and localization phenomena due to their influence on the propagation and interaction of the deformation waves. Such processes include strain rates over $107s-1$ and temperatures reaching the melting point. It should be emphasized, that apart from thermal effects, the anisotropy of damage (both initial and induced by deformation) plays a central role in the overall process. The aforementioned dynamic events are described in this paper in terms of the Perzyna's type viscoplasticity model recently developed by the authors, including the anisotropic damage. The discussed constitutive structure has a deep physical interpretation derived from the analysis of a single crystal and polycrystal behaviors.