Gradient variable cross-section coaxial Bragg grating strain sensor and use method thereof

Abstract

The invention provides a gradient variable cross-section coaxial Bragg grating strain sensor and a use method thereof. The sensor comprises a plurality of single-cycle sensing structures with the same structure, and the single-cycle sensing structures are integrally connected. Each single-cycle sensing structure sequentially comprises an inner conductor, an insulating layer, a metal outer conductor and an outer sheath from inside to outside, wherein the inner conductor, the insulating layer, the metal outer conductor and the outer sheath are coaxially arranged, and the cross-section radius of the insulating layer is in gradient change; and a gradient model of the gradient gradual change insulating layer is constructed by a cubic spline interpolation curve. Compared with a traditional coaxial electric grid sensor, the gradient gradual change insulating layer is continuous in overall structure, the structure is simple, the cost is low, the strain range is wide, the bearing is uniform in the strain process, the structure sensitive, and the response speed is high.

Description

technical field [0001] The present invention relates to the technical field of structural health monitoring, in particular to a gradient variable cross-section coaxial Bragg grating strain sensor and a method for using the same. Background technique [0002] During the whole life cycle of ships, offshore platforms, bridges and tunnels and other large-scale infrastructure, natural and human factors will cause their structures or functions to be damaged to varying degrees. If the damage monitoring is not timely, it will seriously threaten the safety of economic life and property. Therefore, real-time structural health monitoring (SHM) for large facilities is very necessary. As an important part of SHM, non-destructive real-time strain sensors play a decisive role in monitoring response speed, micro-strain resolution, stability, etc. Research on real-time strain sensors has always been a hot spot in the field of SHM, and with the development of related theories Continuous deep...

AI Technical Summary

Problems solved by technology

Due to the limited monitoring range of a single strain gauge, the amount of sensor embedding required for a large-scale strain is huge, so it is somewhat incapable of monitoring the health of large facilities

However, the application of fiber Bragg grating strain sensors is limited due to its fragility and small strain range.

[0003]The strain sensors currently used in structural health monitoring have a small dynamic strain monitoring range, stress concentration and structural slippage during the stress stretching process, resulting in large accuracy errors. Severe wave leakage, large frequency attenuation, plastic deformation of the insulating medium layer, damage to the sensor and cannot be reused, increasing the maintenance cost of the sensor

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