Structural health monitoring of smart civil structures based on fiber Bragg grating sensing technology

The real-time monitoring technologies of smart civil structure using fiber Bragg grating (FBG), including the wavelength demodulation technology of FBG, are researched extensively at home and abroad. To improve the accuracy of demodulation system of FBG sensors, based on a fiber comb filter, a wavelength-demodulation method of FBG was proposed and an experiment platform was designed to demodulate the FBG wavelength for smart civil structure. The reinforced concrete embedded fiber Bragg gratings became the intelligent civil structure on which the experiment of structural health monitoring was done. Experimental results show that, based on a fiber comb filter, the FBG wavelength demodulation method can be used to demodulate the FBG wavelength with high speed and high precision, which can be used extensively in large-scale multipoint monitor engineering. During the experiment, the fiber Bragg gratings embedded in reinforced concrete show good sensing properties, and can respond rapidly to strain with a stable performance.