Optical fibre displacement transducer

Abstract

The invention discloses a fiber grating displacement sensor which comprises a shell, fiber gratings, an equal-strength beam and a measurement probing rod. One end of the measurement probing rod extends into the shell, the shell is provided with a wedge block, a connecting rod and a cushion block, wherein the measurement probing rod is in fixed connection with the cushion block, the cushion block is provided with a cavity, the length of the connecting rod is larger than the length of the cavity, one end of the connecting rod is fixed on the shell, the other end of the connecting rod extends to the cavity, a pulling spring whose aperture is large than the width of the cavity is arranged on the connecting rod, one end of the equal-strength beam is fixed on the cushion block, the other end of the equal-strength beam is connected with a supporting rod, one end of the supporting rod is held against the oblique plane of the wedge block, the fiber gratings are boned on the upper and the lower surfaces of the equal-strength beam in symmetry, the fiber gratings are connected with tail fibers, one end of each tail fiber extends out of the shell. The characteristics of the fiber grating displacement sensor are that the fiber gratings are used to carry out displacement detection, prevents electromagnetic interference, is good in durability and high in measurement precision; the symmetrical bonding of the fiber gratings on the upper and the lower surfaces of the equal-strength beam eliminates the measurement error which may be caused due to temperature change.

Description

A Fiber Bragg Grating Displacement Sensor technical field The invention relates to a detection sensor, in particular to a fiber grating displacement sensor. Background technique In civil engineering, structural health monitoring (SHM) is of great significance to ensure the long-term safe operation of the structure, and displacement detection is one of the most basic measurement items in measurement technology, and is the basis for the measurement of various physical quantities (such as: vibration, displacement, strain, acceleration, etc.). Displacement detection can use a displacement sensor (a sensor used to measure the deformation of engineering structures), which can provide the necessary data for structural health monitoring. The traditional displacement sensor is a resistance strain gauge type. This kind of displacement sensor has poor durability, is susceptible to strong electromagnetic field interference, and has limited information. The results of long-term strain...

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