Wide range fiber grating strain transducer

Abstract

The invention provides a wide range fiber grating strain transducer. The transducer comprises a foil planar spring (1), wherein a fiber grating (2) is positioned in a groove (11) on the longitudinal axis of the planar spring (1); and two ends of the fiber grating (2) are fixed on corresponding positions of the planar spring (1). The wide range fiber grating strain transducer overcomes the defects of plastic deformation, yielding and even cracking easily happened to the prior strain transducer. The strain transducer of the invention can measure wide range strain (+ / -2,500 mu epsilon) through adopting the structure of the planar spring; and through conversion effect of the structure, the strain directly acting on a base material can be effectively reduced, thereby improving the range of measurable strain of the transducer.

Description

technical field [0001] The invention belongs to the field of sensor technology, more specifically it is a large-scale optical fiber grating strain sensor. Background technique [0002] Fiber Bragg Grating is an optical passive device that has developed extremely rapidly in the fields of optical fiber communication and optical fiber sensing in recent years. The strain sensor developed based on fiber grating has the advantages of high sensitivity, small size, corrosion resistance, and electromagnetic radiation resistance, and can meet the measurement needs in harsh working environments such as civil engineering, aerospace, and petroleum industries. Since its sensing signal is directly modulated at the wavelength of light, it is not affected by fluctuations in light intensity, connection loss, and fiber bending loss. It has good stability and high measurement accuracy; in addition, it has the characteristics of wavelength division multiplexing, so multiple Fiber Bragg gratings...

AI Technical Summary

Problems solved by technology

However, there are defects in the measurement of large-scale strain (such as ±2500με), mainly reflected in: the strain is transmitted to the fiber grating through the substrate material used in the above packaging method, and the current yield point of ordinary steel σ s limited (about 200MPa), so the strain that can be measured is also limited (about 1000με), when the measured strain is greater than its yield limit, the steel substrate will undergo plastic deformation, yield, or even fracture, so that the strain sensor is damaged If it is damaged, it is impossible to continue to complete the measurement task, and the selection of materials with high yield point will greatly increase the cost

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