Optical fiber grating acceleration sensor and test method thereof

Abstract

The invention discloses an optical fiber grating acceleration sensor and a test method thereof, relating to the technical field of optical fiber grating vibration sensing. The optical fiber grating acceleration sensor comprises a U-shaped shell, a steel beam, a first optical fiber grating, a second optical fiber grating, a mass block, a spring, damping fluid, a clamping groove, a concave lever, a folding arch beam and a seal cover, wherein the opening end of the U-shaped shell is provided with the seal cover; the inner wall of the U-shaped shell is connected with one end of the steel beam, and the other end of the steel beam is fixedly connected with the folding arch beam; the folding arch beam is fixedly connected with the concave lever; the concave lever fixed to the clamping groove is connected with the mass block; the mass block is connected with the inner wall of the shell by the spring; the first optical fiber grating and the second optical fiber grating are respectively arranged on the folding arch beam; and the damping fluid is filled in the U-shaped shell. The invention realizes the repeated design and use according to the engineering practical demand and changes the system rigidity by conveniently disassembling and replacing folding arch beams with different sizes, thereby realizing the adjustability of sensitivity and natural vibration frequency and achieving the aim of temperature self compensation.

Description

[0001] technical field [0002] The invention relates to the field of fiber grating acceleration sensor testing. Background technique [0003] Fiber grating acceleration sensors have important applications in many fields, such as real-time monitoring in aerospace, large electromechanical equipment, bridge structures, oil surveys, ships, and earthquakes. The fiber grating acceleration sensor embeds the fiber grating inside the substrate material and structure or pastes it on its surface to make it sensitive to the parameter to be measured, and senses the size of the parameter to be measured through the drift of the center wavelength, monitors the vibration of the object, and judges the work State, timely troubleshooting, to avoid major accidents. Traditional electrical acceleration sensors output weak electrical signals, cannot be transmitted over long distances, and have poor reliability in outdoor harsh environments, while fiber gratings can achieve long-distance monitor...

AI Technical Summary

Problems solved by technology

Because the cross-sectional area of ​​the fiber grating is very small and cannot be bent, this structure has the disadvantages that it is not easy to fix with the lever and it is easy to break when the force is directly applied to the bare fiber grating.

The sensor uses a single grating, which can only qualitatively reduce the influence of temperature on the central wavelength of the grating according to the difference in thermal expansion coefficient of the material, and cannot accurately realize temperature self-compensation

Once the design is determined, the change of the mass of the mass block will inevitably lead to the imbalance of the initial state of the system and make the fiber grating have a certain prestress, which reduces the range of the fiber grating strain gauge

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