Optical fiber Bragg grating sensing principle-based temperature-self-compensating intelligent bolt

Abstract

The invention relates to an optical fiber Bragg grating sensing principle-based temperature-self-compensating intelligent bolt, and belongs to the field of optical fiber sensing and structure health monitoring. The optical fiber Bragg grating sensing principle-based temperature-self-compensating intelligent bolt comprises a bolt body 5, an optical fiber 8, a first optical fiber Bragg grating sensor 4 and a second optical Bragg grating sensor 7, wherein the first optical fiber Bragg grating sensor 4 and the second optical Bragg grating sensor 7 are formed in the same optical fiber 8 by carving; the first optical fiber Bragg grating sensor 4 senses temperature and strain; the second optical Bragg grating sensor 7 senses the temperature; an axial sensor implanting hole 6 which penetrates through the bolt body 5 is formed in the bolt body; the optical fiber 8 penetrates through the sensor implanting hole 6; the first optical fiber Bragg grating sensor 4 and the second optical Bragg grating sensor 7 are positioned in the sensor implanting hole 6; a packaging adhesive is injected into the sensor implanting hole 6 to package the first optical fiber Bragg grating sensor 4 in the sensor implanting hole 6; heat-conducting silicone grease is injected into the sensor implanting hole 6 to package the second optical Bragg grating sensor 7. According to the temperature-compensating intelligent bolt, the strain of the bolt in a working state can be monitored online in real time.

Description

technical field [0001] The invention relates to a temperature-compensated intelligent bolt based on the principle of fiber grating sensing, which is used for real-time online monitoring of the tension of the bolt under working conditions, and belongs to the fields of optical fiber sensing and structural health monitoring. Background technique [0002] Bolts are the most important connectors in various large-scale equipment and engineering structures. They are widely used in engineering fields. Accidents caused by bolt looseness, fatigue and corrosion-induced fractures and overloads are often reported. These accidents have caused great damage. Economic losses and casualties; due to its special working state and structural characteristics, it is very difficult to realize real-time online working state monitoring. [0003] Fiber Bragg grating, referred to as fiber grating, is a wavelength modulation optical fiber sensor with a diameter of about 125 μm (micron), and a sensor len...

AI Technical Summary

Problems solved by technology

[0004] Fiber Bragg grating strain sensors are sensitive to temperature changes at the same time, and cannot distinguish between strain and temperature changes by demodulating signals. In engineering applications, fiber Bragg grating temperature sensors must be installed at the same time for temperature compensation, which increases the complexity of the test system.

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