The purpose of the present paper is to study the effect of hybridation, stacking sequences and fiber orientation on the damping properties of unidirectional carbon/flax fiber reinforced epoxy composites. Non-hybrid and hybrid laminates with different stacking sequences were produced by molding vacuum process. Free vibration tests with an impulse technique were performed on test specimens to investigate the dynamic behavior. Finite element analysis was used to model damping to evaluate the different energies dissipated in the material layer directions of the carbon/flax composites. Close agreement was found between the experimentally measured values and those derived from the numerical simulation for the damping coefficients. The results obtained show that flax layers had a significant effect on damping properties.

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The aim of the present study is to investigate the mechanical behavior of carbon/flax hybrid composites under static and fatigue tensile loading. The failure characteristics and parameters used in the fatigue tests were deduced from the static ones. The effect of the applied stress level, hybridization and stacking sequences on the stiffness, hysteresis loops, dissipated energy and damping, were studied for a various number of cycles during fatigue tests. The Wohler S-N curves were constructed to investigate the effect of hybridization on the fatigue behavior. The results obtained show that the fatigue performance as well as the fatigue resistance increase with the increase of the volume fraction of carbon fiber. Nevertheless, the damping ratio and the fatigue life increase with the increase of the flax fiber volume fraction.