p. 87-88
A small-diameter fiber Bragg Grating (FBG) sensor is easily embedded in adhesive layer between a repair patch and a structure, since the diameter of this sensor is very small. Thus, the FBG sensor was embedded into the adhesive layer to detect the debonding between the patch and the substrate. First, it was confirmed that debonding progress of the patch was not affected by embedment of the FBG sensor. Secondly, it was experimentally and theoretically revealed that the delamination length could be evaluated quantitatively by the comparison of intensity ratio of the two peaks in the reflection spectrum from the sensor.