Bridge structure monitoring system based on practical FBG

To satisfy bridge health monitoring and maintain, a novel low cost sensing system for simultaneous measurements of temperature, strain and pressure based on practical fiber Bragg grating (FBG) is reported in this paper. The main principles of multi-parameter are introduced. A wavelength scanning demodulation system based on continuous wave tunable frequency is designed. The practical FBG sensors have been successfully used in monitoring cable-stayed bridge during construction stage and service time. The experimental results indicate that practical FBG sensors can monitor the structure parameters for a long time, as well as have higher stability. The system can monitor the strain and vehicle flux of important position accurately. FBG sensors can not only supply precision data for bridgepsilas static and dynamic testing but also supply gist for bridgepsilas working state assessment and health diagnosis.