HYGROTHERMAL EFFECTS ON FATIGUE BEHAVIOR OF NATURAL FIBERS COMPOSITES

The aim of this work is to determine the influence of hygrothermal ageing on the mechanical proprieties and fatigue proprieties of natural fiber composite specifically of quasi-isotropic flax/epoxy composite. The result of quasi-static tensile test shows the degradation of proprieties of this material. Fatigue test were perfomed at 70% and 80% of ultimate tensile stress. The results show a great dissipation energy for ageing samples in the beginning of the fatigue cycle compared with unaged sample. Acoustic emission were used to follow the evolution of damage in this material and to characterize the mechanism damage in fatigue mode. Most damage of ageing sample was shown during the fatigue test compared with unaged and fiber pull-out damage mechanism was grown with ageing.