Creep Load Conditions

Abstract

Polymer-based adhesives that have been especially designed to feature a high degree of toughness, flexibility, or, even deliberately, viscoelastic properties exhibit a pronounced time-dependent stress-strain behavior under static mechanical load conditions. Therefore, a suitable mechanical approach to describe and experimentally access phenomena related to creep in polymers and adhesives needs to consider elastic as well as viscous material properties. Creep occurs at load levels below the yield strength, and particularly, creep of viscoelastic materials by definition is assigned to reversible deformation being able to recover after unloading. In technical practice, the term creep is often being used to describe arbitrary time-dependent strain including viscous and elastic-viscous behavior. The concept of generating mechanical substitute models consisting of a combination of spring (elastic) and dashpot (viscous) elements dates back to the late eighteenth