Integrated temperature self-compensation fiber grating strain sensor and its method for monitoring cable force

Abstract

A temperature-self-compensating fiber-integrated bragg grating strain transducer comprises a fiber bragg grating transducer body composed of two bare fiber bragg gratings with the same model but different wave bands, an elastic sheet composed of high-elasticity metal thin sheets, clamping pieces, bases, a Z-shaped movable piece composed of L-shaped steel plates and a metal frame. The metal frame is provided with a frame shaft hole and a frame connecting shaft, and a connecting shaft of the Z-shaped movable piece penetrates through the frame shaft hole to be fixedly connected with the base II through the clamping piece II and can relatively move in the frame shaft hole. One end of the elastic sheet is fixedly connected with the L-shaped plates of the Z-shaped movable piece, and the other end of the elastic sheet is fixed on the metal frame. The frame connecting shaft is fixedly connected with the base I through the clamping piece I. A cantilever beam stress structure is formed by the frame, the Z-shaped movable piece, the elastic sheet, the bases and the clamping pieces. Under the working state, the two bases are fixed on the surface of a component to be tested in a bolting or welding mode, and when the component to be tested is strained, the bases and the Z-shaped movable piece are driven to drive the elastic sheet to deform, and then the fiber bragg gratings deform.

Description

technical field [0001] The present invention relates to a device and method for indirectly measuring the strain on the surface of the anchor cup using a strain sensor, in particular to a cable force sensor based on fiber grating technology and a method for monitoring the force of the cable. The sensor can be installed on the anchor surface of the cable to monitor the force or strain of the cable, and can also be used to measure the stress and deformation of steel, concrete beams, columns and other structural parts in civil and architectural structures. Background technique [0002] The cable force of the cable directly determines the working status of cable-stayed bridges, suspension bridges, arch bridges and other cable-stayed buildings. Using accurate methods to monitor cable force is a necessary means to ensure its smooth construction and safe operation; cable force measurement is commonly used Pressure measurement method, magnetic flux method, frequency method and other ...

AI Technical Summary

Problems solved by technology

[0003] Although the existing fiber grating sensor is an ideal long-term measurement sensor, it has the advantages of high measurement accuracy, good durability, and is not easily affected by the environment (electromagnetic field, humidity, chemical corrosion, etc.), but it also has its own shortcomings: the fiber grating is easy to Brittle and easy to damage, the influence of temperature is relatively large. When temperature and strain act at the same time, there is a problem of cross-sensitivity between strain and temperature

[0007] 2. The sensor packaging method proposed in this patent is simple, and the epoxy resin packaging also has the problem of exposed aging

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