A High Sensitivity Fiber Bragg Grating Strain Sensor

Abstract

The invention discloses an optical fiber grating strain sensor with high sensitivity, and belongs to optical fiber sensor technologies. The optical fiber grating strain sensor comprises bottom-layer sheet metal, middle-layer sheet metal and top-layer sheet metal which are detachably connected with one another. A strain measuring grating is mounted on the top-layer sheet metal, and the bottom-layersheet metal can be fixed onto a to-be-measured object; lever mechanisms are arranged in the top-layer sheet metal and the middle-layer sheet metal, and deformation of the to-be-measured object can betransmitted via the cascaded lever mechanisms between layers and can be amplified on the strain measuring grating. The optical fiber grating strain sensor has the advantages that the optical fiber grating strain sensor is of a three-layer sheet metal cascade structure, strain of the to-be-measured object can be amplified by multiple stages by the aid of the lever mechanisms, 'sensitivity enhancement type' amplification and 'centralization type' amplification theories are adopted for amplification structures, accordingly, amplification factors can be obviously enlarged, and the optical fiber grating strain sensor is high in sensitivity; the optical fiber grating strain sensor is simple in structure and high in sensitivity, is small and can be used for measuring small structural strain.

Description

technical field [0001] The invention belongs to the optical fiber sensor technology and relates to a high-sensitivity optical fiber grating strain sensor. Background technique [0002] As a new type of fiber optic passive device, the fiber optic grating sensor has the advantages of all-optical transmission, anti-electromagnetic interference, corrosion resistance, high electrical insulation, low transmission loss, wide measurement range, easy multiplexing into a network, and miniaturization. It has received widespread attention worldwide and has become one of the fastest-growing technologies in the field of sensing, and has been widely used in civil engineering, aerospace, petrochemical, electric power, medical, shipbuilding and other fields. [0003] Strain measurement is an important means to monitor the safety status of structures, and the strain resolution and strain range required by different applications and different material structures are different. At present, the...

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Problems solved by technology

However, in the case of small strain measurement, the strain sensitivity is too low and the strain range is too large

[0004] At present, some researchers have proposed some sensitivity-enhancing structures, such as patents 201220154883.8 and 201220207094.6, which mainly increase the strain sensitivity by controlling the distance between the mounting blocks to be greater than the distance between the adhesives at both ends of the fixed fiber grating. The sensor of the method has a large volume and a heavy structure, and is not suitable for measuring the strain of a small structure.

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