Effect of water ageing on the mechanical and damping properties of flax-fibre reinforced composite materials

The aim of this work is to study the effect of water ageing of quasi-Unidirectional Flax fibre Reinforced Epoxy (UFRE) composites on their mechanical and damping properties. The studied composites were manufactured by press platen process and subjected to water immersion at room temperature. Mechanical and damping properties of unaged and aged materials were investigated using free vibrations. Next, they were dried and tested to study the reversibility of the variation of those properties caused by water ageing. The results showed that water uptake induces a decrease in the bending moduli and an increase in loss factors compared in term of ageing time. It was also proven that those variations are practically reversible in the case of loss factors but irreversible in the case of bending moduli.