Large-range fiber Bragg grating displacement monitoring device and system

Abstract

The invention provides a large-range fiber Bragg grating displacement monitoring device. The device is characterized by comprising a strain acquisition and transmission component and a measurement component, wherein the strain acquisition and transmission component is used for monitoring the strain of a to-be-detected target and correspondingly zooming out the strain into small strain; the measurement component is used for measuring the wavelength change of a fiber Bragg grating caused by the strain; the rear end of the strain acquisition and transmission component is connected with the to-be-detected target, and the front end of the strain acquisition component is connected with the measurement component. The device converts the large strain of the to-be-detected target object into smallstrain of the front end of the displacement acquisition and transmission device through the rear end of a displacement acquisition and transmission device by establishing a strain transmission mechanism for the large strain of a matrix and the small strain of the fiber Bragg grating; the displacement monitoring device is used for measuring the small strain of the front end of the displacement acquisition and transmission device, and finally a processor is used for calculating and obtaining the displacement corresponding to the large strain of to-be-detected target.

Description

technical field [0001] The invention relates to the field of engineering measuring tools, in particular to a large-range optical fiber grating displacement monitoring device and system. Background technique [0002] In engineering structures, large displacement responses will affect the reliability of the structure, so it is particularly important to monitor the deformation of structures such as bridges, houses, slopes, foundation pits, and pile foundations. Traditional monitoring methods have low monitoring efficiency, high measurement cost, low degree of automation and low measurement accuracy. In recent years, due to its intelligent real-time monitoring, fiber optic sensors have a huge application market in various industries. In particular, the quasi-distributed fiber Bragg grating, as the most widely used and mature fiber sensor technology, has the characteristics of light weight, small size, high precision, high temperature resistance, corrosion resistance, and intell...

AI Technical Summary

Problems solved by technology

[0003] However, the maximum strain that can be accurately measured by existing fiber gratings is only ±3000uε, and the measurement range is small, so it is impossible to accurately measure structures such as foundation pits and slopes that have large strain deformation.

In other words, how to use fiber grating sensors to measure large deformation is a technical difficulty in engineering research. Many scholars have tried many new methods of large strain detection, such as stretching prestressed steel strands to 5000uε and then pasting fiber gratings. Prestress measurement method, but the above method is complex in structure, difficult to process and the measurement accuracy cannot meet the preset requirements

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