Full-dimension distributed and partial high-precision co-linear optical fiber sensing method

Abstract

The invention provides an optical fiber sensing method which takes a full-scale distribution type and has locally and highly precise collineation, and a system of the optical fiber sensing method comprises the parts of a Brillouin sensing demodulation device, a fiber grating demodulation device, an optical switch (or a coupler) and an FRP-FBG-OF sensing probe, etc. One or a plurality of fiber gratings are written onto an ordinary single mode fiber with arbitrary length and made into the sensing probe through the encapsulation of FRP, and the sampling optical switch or the coupler is respectively connected with the fiber grating demodulation device and a Brillouin distributed testing system, thus forming an intelligent sensing monitoring system which implements the large-scale, full-distributed and locally and highly precise testing of structural damage, achieves the full-scale damage positioning and quantitative testing of important projects and the mutual checking effect, and provides complete, direct and reliable information for structural safety evaluation. The optical fiber sensing method is especially applicable to structural damage monitored objects which are characterized by wide distribution range, long distance and concealed position, etc., and has the advantages of compact system, low cost, strong operability, good stability and durability and reliable result, etc.

Description

(1) Technical field [0001] The invention relates to the field of structural intelligent monitoring, in particular to an optical fiber sensing technology of full-scale Brillouin distributed testing and local high-precision optical fiber Bragg grating collinear compounding. (2) Background technology [0002] Major infrastructure, such as space structures, bridges, tunnels, hydraulic embankments, natural gas or oil pipelines, highways, railways, slopes, lifeline pipelines and other large, long-span structures, under the joint action of various loads and external environments Damage can occur, seriously affecting the safety, durability and comfort of the structure. This type of structural damage often has distributed characteristics such as wide distribution, long distance, and hidden monitoring parts, so that the traditional high-precision single-point or quasi-distributed monitoring methods are not competent, and the pure distributed monitoring technology still exists at prese...

AI Technical Summary

Problems solved by technology

In practical engineering applications and laboratory research, some relevant research scholars have simply combined high-precision fiber grating sensors and Brillouin distributed technology to monitor the strain of structures. This combination is a structural combination, that is, in In addition to the deployment of distributed sensing optical fibers in the structure, high-precision local fiber grating sensors are additionally deployed in some important positions of the structure. The sensor layout of this monitoring system is relatively difficult, the wiring is complicated, the layout cost is high, and the reliability is low.

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