Fatigue behavior of optical fiber sensor embedded in smart composite structures

摘要

Fatigue behavior of the optical fiber sensors embedded in composite laminate was studied. The fatigue life of the embedded optical fiber was investigated by measuring the intensity change of the laser signal transmitted through it. Test specimensconsisted of three types of stacking sequences; [0{sub}6/OF/0{sub}6]{sub}T, [0{sub}2/90{sub}4/OF/90{sub}4/0{sub}2]{sub}T and [0{sub}3/90{sub}3/OF/90{sub}3/0{sub}3]{sub}T. From the experiment, it was observed that the optical fiber sensor embedded incomposite laminate under fatigue loading was fractured at lower stress level than the average static stress at which the fracture of the embedded optical fiber within the laminate occurred. It was found that the fatigue life of the optical fiber embeddedin cross-ply laminate was closely related with the growth of transverse matrix crack. On the other hand, the fatigue fracture of the embedded optical fiber within the unidirectional-ply laminate occurred due to the growth of internal defects of opticalfiber. The decrease in fatigue life of the optical fiber embedded in the unidirectional-ply laminate is relatively small compared to the cross-ply laminate case.