A study of the coupling between the phenomena of water absorption and damage in glass/epoxy composite pipes

Abstract

An analysis of the influence of moisture on the mechanical properties and kinetics of damage is presented. The material studied is a glass/epoxy laminate pipe for fluid circuit applications. The tubular specimens have been obtained by the filament-winding technique. In the first part of the paper, the diffusion law and the influence of mechanical damage on absorption are presented, while in the second part, the change in the kinetics of the damage is studied for various levels of water content. Mechanical tests, under tension and internal pressure with fixed ends, demonstrate an increase in the rate of damage as a function of water content. The damage rate acceleration is taken into account in a multiaxial behaviour model. The effect of water content in the material is introduced into this model by using a damage-associated variable depending on the moisture level.