THERMODYNAMIC RELAXATION - A CONTRIBUTION TO CONSTITUTIVE LAWS FOR COMPLEX MATERIALS

In order to establish constitutive laws for materials, we present in t his paper a point of view based on thermodynamic relaxation laking int o account internal variables, in accordance with previous presentation s. The originality of this work lies essentially on the fact that we u se a normal mode description near the equilibrium and that the corresp onding distribution law is built on fluctuation concepts. Another impo rtant key is the introduction of non linear couplings between normal m odes far From the equilibrium. The physical meaning of these effects i s related to the kinetic activation state representation of the relaxa tion times. Various applications chosen in the field of mechanical pro perties are proposed here.