Effects of water absorption on mechanical properties of hemp fiber composites

Effects of water absorption on mechanical properties of hemp fiber composites have been studied. Finite difference method modeling of water absorption in these composites showed the diffusion to be Fickian in nature. The residual tensile and flexural properties showed immediate decline following immersion in water, the loss in modulus being more pronounced than the loss in strength. The fracture of tensile tested composites following immersion in water was found to be more ductile than brittle, which showed the evidence of shear stresses being more significant in these conditions. For impact damaged composites immersed in water, most of the degradation in residual tensile properties occurred within first 100 h of immersion in water at same impact energy level and further immersion in water for up to 400 h did not result in any further degradation. No deterioration in fatigue strength and fatigue sensitivity of composites following immersion in water was observed. POLYM. COMPOS., 2012.