C

Abstract

The creep compliance is an exponentially decreasing function of time. It can be considered to consist of three components. Firstly, the unrelaxed compliance characterising the immediate elastic response and the limiting value of the overall creep compliance at short times, i.e. characteristic of the ‘glassy’ behaviour of the material. Typically this has a value of about 10⁻⁹ Pa⁻¹. Secondly, the compliance component characterising viscous flow at very long times, typically having a value of about 10⁻⁵ Pa⁻¹. Its limiting value is the equilibrium or relaxed compliance. Both these components are time independent. The characteristic viscoelastic behaviour at intermediate times provides the third component and is indicated by the compliance component for the retarded elastic response. In this transition region, this component dominates behaviour.