An experimental investigation on reliability of FBG sensors packaged with CFRP

The paper made an experimental investigation on reliability of fiber Bragg grating (FBG) sensors packaged with carbon fiber reinforced polymer (CFRP) which would be used in fatigue test of wind turbine blades (WTBs). More and more FBG sensors are applied to the full-scale fatigue test of WTBs. For the size of FBG sensor is very small and easy to break, it must be packaged before used. Compared with other packaging materials, fiber reinforced polymer (FRP) is more suitable for packaging FBG sensors used in WTBs because of its good compatibility with the surface material of the blade. The performance of FRP packaged FBG sensor has been studied in the available literatures, while influences of different FRP layers and sizes on the reliability of FRP packaged FBG sensors are unknown. Thus, in this paper, CFRP is chosen as the packaging material of FBG sensors, and the influences of packaging layers and sizes on the reliability of CFRP packaged FBG sensors are studied by a series of experimental tests. The results show that the orientation angles and lengths have negligible influences on the reliability of CFRP packaged FBG sensors, the layers and sizes of CFRP must be considered when packaging FBG sensors.