Fiber Bragg grating sensors for arch bridge suspender health monitoring

Firstly, Wavelength shift of Fiber Bragg Grating (FBG) sensors that monitor the arch bridge suspender tension due to strain or temperature change has been studied theoretically, and theirs sensitivity coefficient is gotten through calibrating experiment. Secondly, the FBG strain and temperature sensors have been successfully installed in some key suspenders of Sichuan Ebian Dadu river arch bridge. Techniques of installation of FBG sensors and suspender repairing have been explored in-service arch bridge. Thirdly the change of suspender strain and temperature, and the effect of the same loading to different length suspender have been monitored with the FBG sensors. The monitoring results show that the FBG sensors can monitor correctly the change of traffic loading and temperature, possible fatigue damages, FBG sensors are more adaptive to long-term structural health monitoring than the electric strain gauges.