Second approximation methods for determining the relaxation time spectrum of a viscoelastic material

Abstract

Second-approximation methods are given for deriving the distribution function of relaxation times of a viscoelastic material from experimental measurements of stress relaxation after sudden strain, stress relaxation after cessation of steady-state flow, the real and imaginary parts of the complex dynamic rigidity, and the real part of the complex dynamic viscosity. The numerical coefficients required for the calculations are tabulated, and the methods are illustrated by application to experimental data on solutions of polyvinyl acetate.