Modelling the linear viscoelastic behavior of silicate glasses near the glass transition point

TL;DR

This paper develops a thermodynamics-based model for the viscoelastic behavior of silicate glasses near the glass transition, considering a distribution of relaxation units and fitting experimental data.

Contribution

It introduces a novel model that describes the viscoelastic response of glasses using energy landscape concepts and thermodynamic laws, fitted to experimental data.

Findings

Model accurately fits torsional dynamic test data

Reveals distribution of activation energies in glass relaxation

Provides insights into glass behavior near transition point

Abstract

A model is derived for the viscoelastic response of glasses at isothermal uniaxial deformation with small strains. A glass is treated as an ensemble of relaxing units with various activation energies for rearrangement. With reference to the energy-landscape concept, the rearrangement process is thought of as a series of hops of relaxing units (trapped in their potential wells on the energy landscape) to higher energy levels. Stress-strain relations are developed by using the laws of thermodynamics. Adjustable parameters are found by fitting experimental data in torsional dynamic tests on a multicomponent silicate glass at several temperatures near the glass transition point.