Characterisation and modelling of aging of composites

The aim of this study was to better understand the aging of glass fibre–epoxy composites exposed to water and loading and to predict effects on structure lifetimes. Diffusion was investigated by gravimetric methods to determine sorption kinetics for different conditions. Fickian diffusion was observed. Decreases of mechanical properties as a function of diffusion were observed. Damage by cracking and the coupling with water uptake were then studied. A model taking into account effects due to water and/or mechanical loading is proposed which allows the continuous evolution of rigidity during aging to be predicted at all stages of water absorption and matrix cracking.