... Thermodynamics – Systems in Equilibrium and Non -Equilibrium 76 In the case of inelastic behaviour, we define a scalar function called the dissipation potential (,), convex and ... intervenes here. In viscoplasticity, a continuously differentiable dissipation potential, definite positive, convex and contains the origin, can be defined: Thermodynamics – Systems in Equilibrium ... (1 07) ϵ,=+ (108) Specialising to a linear isotropic porous material, after substituting (1 07) into (76 ) and taking into consideration the decomposition into...