Effects of microstructures of smart fiber composites on embedded fiber Bragg grating sensors

This paper presents the results of an investigation on the effects of composite microstructures on the spectral response of fiber Bragg grating (FBG) sensor embedded in smart carbon-epoxy fiber composite, based on the mechanical finite element analysis and optical coupled mode theory. The FBG sensors are embedded in the directions parallel or intersected to the axis of reinforcing carbon tows. It shows that FBG sensors have good linear spectral responses for axial loads in both cases of sensor arrangements, and their sensitivities are close to each other. For lateral compression loads, however, the parallel arrangement has much smaller effects on the spectra than that of intersected arrangement, and thus is proposed for the sensing applications.