The aim of this tutorial survey is to revisit the basic theory of relaxation processes governed by linear differential equations of fractional order. The fractional derivatives are intended both in the Rieamann-Liouville sense and in the Caputo sense. After giving a necessary outline of the classical theory of linear viscoelasticity, we contrast these two types of fractional derivatives in thei...

The result of Da Prato and Sinestrari [3] concerning the non-autonomous evolution operators of hyperbolic type for the equation u′(t) = A(t)u(t) + f(t), t ∈ [0, T ], w(0) = w0, is applied to the study of u′(t) = A(t) [ u(t)+ ∫ t −∞ G(t, s)u(s)ds ] +K(t)u(t)+f(t), t ∈ [0, T ], u(s) = φ(s), s ≤ 0, which models linear viscoelasticity. Here A(·) satisfies all the requirements of Kato’s semigroup ap...

Understanding interpenetrated polymer networks mechanical interactions by micromechanics modeling of their linear viscoelasticity.

We develop a continuum theory of linear viscoelastic response in oriented monodomain nematic elastomers. The expression for dissipation function is analogous to the Leslie-Ericksen version of anisotropic nematic viscosity; we propose the relations between the anisotropic rubber moduli and new viscous coefficients. A new dimensionless number is introduced, which describes the relative magnitude ...

Within the framework of linear viscoelasticity this paper deals with the study of spatial behavior of solutions describing harmonic vibrations in a right cylinder of finite extent. Some exponential decay estimates of Saint–Venant type, in terms of the distance from the excited end of the cylinder are obtained from a first-order differential inequality concerning an appropriate measure associate...

A non-linear equation in viscoelasticity of the form ρuρtt(t, x) = φ(u ρ x(t, x))x + ∫ t −∞ F (t− s)φ(ux(s, x))xds+ ρg(t, x) + f(x), t ≥ 0, x ∈ [0, 1], (0.1) u(t, 0) = u(t, 1) = 0, t ≥ 0, (0.2) u(s, x) = v(s, x), s ≤ 0, x ∈ [0, 1], (0.3) (where φ is non-linear) is studied when the density ρ of the material goes to zero. It will be shown that when ρ ↓ 0, solutions u of the dynamical system (0.1)...

In this paper the authors propose a novel method to study the local linear viscoelasticity of fluids confined between two walls. The method is based on the linear constitutive equation and provides details about the real and imaginary parts of the local complex viscosity. They apply the method to a simple atomic fluid undergoing zero mean oscillatory flow using nonequilibrium molecular dynamics...