The Influence of Aqueous Environment, Temperature and Cyclic Loading on Glass-Fibre/Epoxy Composite Laminates

Abstract

An experimental investigation has been carried out to study effects of immersion in distilled water, temperature (ambient and 90°C) and cyclic loading on the mechanical behaviour of E-glass fibre reinforced epoxy matrix composite laminates. Three types of laminates were investigated: cross-ply, multi-directional and angle-ply. Following immersion for over four months, a steady state moisture uptake was reached for the ambient temperature specimens while no such state of saturation was observed for those immersed at 90°C temperature. Fatigue life curves of the immersed specimens are compared to those of the dry ones and the failure modes are discussed. Immersion in 90° temperature results in excessive swelling and cracking, and considerable reduction in the fatigue resistance. The inter-relation among accumulated creep strain due to cyclic loading, crack density variation and stiffness reduction are also discussed.