Fiber Bragg grating sensor monitoring techniques and health diagnosis of arch bridge suspenders

The relationship between the wavelength of the arch bridge suspender tension monitoring FBG sensors and the strain and temperature has been studied theoretically, and the sensitivity coefficient is gotten through calibrating experiment. The FBG strain and temperature sensors have been successfully installed in some key suspenders of Sichuan Ebian Dadu river arch bridge. The installation of FBG sensors and suspender repair have been explored in-service arch bridge. The change of suspender strain and temperature, and the effect of the same loading traffic on different length suspender have been monitored under traffic loading 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, and FBG sensors are more adaptive to long-term structural health monitoring than the electric strain gauges.