Positioning of Damage in Crack Structure of Steel Girder with Distributed Detection Using Brilouin Optical Time Domain Analysis (BOTDA) Fiber Optic Sensor

摘要

Based on the structure and demodulation principle of Brilouin Optical Time Domain Analysis (BOTDA) fiber optic sensor, this study discussed over strain transmitting efficiency and signal value of bounded BOTDA fiber optic sensor through experiments. Then, factors influencing monitoring signal of BOTDA fiber optic sensor was summarized after performing lots of comparison experiments. Moreover, influence of spatial resolution, spatial spacing interval and average number as well as monitoring mode for cracks were studied. Finally, we introduced the application of BOTDA fiber optic sensor in model test. BOTDA fiber optic smart bar embedded with Fiber Reinforce Plastic (FRP) is proved to be capable of discovering deformation of structure. BOTDA fiber optic sensor which is flexible in installation and easy to survive is applicable for construction environment and structure monitoring in civil engineering.