Abstract
The authors have applied newly developed small-diameter Fiber Bragg Grating(FBG) sensors, whose cladding was 40μm in diameter, for the detection of transverse cracks in Carbon Fiber Reinforced Plastic(CFRP) quasi-isotropic laminates. Loading/unloading test was carried out, and reflection spectra from the FBG sensor were measured at various tensile strain. When transverse cracks occured in the laminate, the shape of reflection spectrum was drastically distorted, and the Full Width at Quarter Maximum(FWQM) increased in proportion to the transeverse crack density in the 90° ply. This change in the form of the spectrum could be confirmed by the theoretical calculation.
