Method for Bending Measurement Using Fiber Optic Bending Sensor with Air Gap

Abstract

The invention discloses an optical fiber bending sensor having an air gap and a bending measurement method. The optical fiber bending sensor employs a single mode step optical fiber comprising a fiber core and a wrapping layer. An upper part of the optical fiber is provided with a gap with a certain width and a certain depth, and therefore the optical fiber bending sensor having the air gap is formed. The optical fiber bending sensor having the air gap is adhered to a measurement structure, and an open end faces outward; when the optical fiber bends along with the measurement structure, intensity of light going through the air gap varies as an angle of bending changes; a bending radius of the measurement structure can be obtained via light intensity attenuation of the light going through the air gap. The optical fiber bending sensor having the air gap and the bending measurement method can be used for directly measuring light intensity, no expensive equipment such as a spectrum analyzer or the like is needed, and measurement sensitivity is improved.

Description

technical field [0001] The invention relates to a bending measurement method using an optical fiber bending sensor with an air gap, and belongs to the technical field of stress and strain measurement. Background technique [0002] The deformation and bending of the structure is an important parameter. Traditional strain gauges use the relationship between strain and curvature to indirectly infer the curvature of structures, but when the thickness of the structure is thin, the strain may be small, which makes the measurement of strain gauges more difficult. [0003] Optical fiber sensor has the advantages of high temperature resistance, high sensitivity, fast response, anti-electromagnetic interference, corrosion resistance, good electrical insulation performance, flame-proof and explosion-proof, small size, simple structure, and easy to form a telemetry network with an optical fiber transmission system. Optical fiber Bragg sensor is one of the research hotspots of optical f...

AI Technical Summary

Problems solved by technology

When the external environment (such as temperature) is greatly affected, additional equipment such as an expensive spectrum analyzer is required

The optical fiber surface of the light intensity modulation optical fiber sensor has not been processed, and it is only made of the principle that the light intensity loss of the optical fiber increases suddenly when the optical fiber is bent with a large curvature. Therefore, the sensitivity is very low

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