VISCOELASTIC CONSTANTS OF A SODA-LIME-SILICA GLASS

A complete development of the viscoelastic constants is given in the f ramework of the viscoelastic theory using the definition of Tschoegl a nd the notion of moment introduced by Gy et al. for the linear viscoel asticity. Viscoelastic constants were considered as 'constants' becaus e these dimensionless parameters do not change with loading level for a linear viscoelastic material. In addition, for a thermorheologically simple viscoelastic material, some of them are temperature-independen t, whereas others follow the temperature-dependence of the Poisson rat io. Since some of them have a simple physical meaning, all models have to take them into account for simulating mechanical behavior of visco elastic materials. Experimental measurements for some of viscoelastic constants under shear and uniaxial loadings allow determination of bul k equilibrium elastic modulus and other viscoelastic constants, used f or describing hydrostatic pressure and biaxial behavior.