Concrete crack detection method based on optical fiber sensing network and microbending principle

The design idea and complete system design scheme of crack monitoring system based on fiber micro-bending principle are proposed. The simulation test platform of crack monitoring system is constructed, which provides theoretical and technical guarantee for crack monitoring test based on fiber sensing. A crack monitoring technique based on oblique fiber optic sensing network is proposed, and the angle of skew between the fiber and the crack is equal to 60. Time is the best sensor network deployment solution. The technical method has the advantages of simple process, low cost, easy implementation, and ability to realize distributed measurement. A crack monitoring technology based on microbend sensitized fiber sensor head is proposed. The quantitative relationship between optical loss and crack width of sensitized fiber sensor network is established, and microbend sensitized fiber sensor head is designed and fabricated. The technical method can accurately locate and accurately measure concrete cracks under the condition of unknown crack direction, and the test precision reaches 0.05 mm, which is completely suitable for high-precision and distributed monitoring of concrete cracks, and can be used in concrete bridges and dams. Widely promoted and applied in crack monitoring such as tunnels.