Meaning
Quantitative measure of the ease with which a material deforms over time under a constant level of mechanical stress. Unlike purely elastic materials that reach a final shape instantly, substances with high viscoelastic compliance continue to stretch or compress for as long as the force is applied. This property is expressed as the ratio of the increasing strain to the applied stress.
It is a fundamental parameter for describing the creep behavior of plastics and resins.
Creep Function
Mathematical curves derived from long term testing show how the deformation evolves from the moment of loading. If the viscoelastic compliance of a component is too high, it may eventually sag or lose its fit within an assembly. This function ensures that parts remain within their dimensional tolerances throughout their expected service life.
Temperature Influence
Thermal energy increases the mobility of the molecular chains, leading to a noticeable rise in the observed rate of deformation. A material that appears stiff at room temperature might show high viscoelastic compliance when exposed to operational heat. Testing across a range of temperatures is required to build a complete profile of how the material will perform in the field.
This sensitivity is particularly high near the glass transition point where the compliance can increase by several orders of magnitude over a narrow temperature span.
Molecular Mobility
Internal friction between polymer strands dictates the speed at which the material responds to an external load. High viscoelastic compliance is usually linked to a structure with fewer cross links or more free volume between the chains. By adjusting the chemical formulation, manufacturers can tune this property to meet the specific requirements of a vibration damper or a structural support.
