Free Energies for Nonlocal Materials

Abstract

When nonlocal materials are considered, the classical laws of thermodynamics must be modified by expressing these laws in terms of internal powers or by introducing directly into them suitable extra fluxes, characteristic of the material under consideration [80], as discussed in some detail in Section 3.7. The first formulation, in terms of internal powers, is more general then the second one, since it is defined a priori by means of the constitutive equations, by taking into account the power balance laws; in the second method there is the problem of introducing a posteriori the vector fluxes in order that compatibility with the laws of thermodynamics be satisfied.