6533b7d3fe1ef96bd126111b

RESEARCH PRODUCT

Effect of moisture uptake on flax-reinforced composite laminates: influence on dynamic and quasi-static properties

subject

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International audience; This study proposes to investigate the effect of moisture uptake on a wide spectrum of mechanical behaviours of unidirectional flax fibre-reinforced epoxy laminates. It includes tensile monotonic and fatigue testing. Results show that UD flax-epoxy composites, whenexposed to hygrothermal conditioning at 70°C and 85% RH, exhibit a diffusion kinetic which follows a one dimensional Fickian behaviour. The mass uptake at equilibrium is approximately 3.3 % and the diffusion coefficient 6.5 10-6 m2.s-1. Water vapour sorption is shown to induce a significant change in the shape of the tensile stress-strain curve. Contrary to all expectations, water saturation does not degrade the monotonic tensile strength of such a flax-epoxy composites and induces an increase in the fatigue strength for a high number of cycles