The effects of water ageing on the tensile static and fatigue behaviors of greenpoxy–flax fiber composites

Abstract

This work presents the experimental results of the effect of water ageing in flax fibers reinforced greenpoxy resin matrix composite materials. The experimental study was carried out on two cross-ply laminates ([0/90] s and [+45/−45] s ). First, the water uptake of the two composite materials was studied. Second, the mechanical properties were identified as a function of the immersion time. The results obtained show that the Young's modulus of composites decreases progressively to 26% for [0/90] s specimens and 46.36% for [+45/−45] s specimens after 30 days of ageing. Finally, the effects of interactions between water ageing and cyclic fatigue behavior were studied. We consider stiffness loss, hysteresis curves, energy dissipation and loss factor versus number of cycles as a function of different immersions time. A significant decrease in the mechanical characteristics of the composites as a function of the immersion time is observed. [+45/−45] s specimens are more sensitive to both fatigue and water ageing phenomena.