Effect of aqueous environment and temperature on glass-fibre epoxy resin composites

The main objective of this experimental investigation is to study the absorption behaviour of fibre-glass reinforced epoxy matrix composite laminates immersed in distilled water, in ambient and 90 degreesC temperatures, and its effect on the mechanical properties. A comparative study is carried out to evaluate the properties of dry and water immersed specimens, and to investigate damage caused by the aqueous environment and temperature. It is found that the degree of damage strongly depends on the immersion temperature. The fracture surfaces in three different environments are studied using a scanning electron microscope and micro-macro damage correlation is established. The threshold strain for the matrix crack initiation increases when the laminated are immersed in ambient water in comparison to that of a dry environment. Immersion at high water temperature leads to embrittlement of the glass fibres and matrix blistering resulting in a slight decrease in threshold crack initiation strain.