Fiber grating accelerometer with adjustable sensitivity

Abstract

A fiber grating accelerometer with adjustable sensitivity belongs to the machinery vibration testing technology field, and comprises a housing, and a fiber grating, a L-type rotary shaft, a support, a mass block, an isostrenth beam, a motion steel shaft, and a steel sheet arranged in the housing; the rotary shaft is supported on the housing bottom plate by the support, and penetrates the steel sheet; one end of the rotary shaft is connected on the housing end plate, and the other end is connected with the mass block; the mass block freely slides along the rotary shaft; the isostrenth beam with the bonded fiber grating is fixed on the housing end plate, has the same height with the rotary shaft center, and the end of the isostrenth beam is connected with a motion steel shaft; the motion steel shaft is connected with the edge of the steel sheet on the rotary shaft. The mass block is provided with a plurality of shifts on the rotary shaft; according to measuring requirements of a measured object, the mass block can slide on the L-type rotary shaft so as to select the property shift, thus flexibly adjusting the sensitivity and measuring range, and improving measuring precision in the selected measuring range.

Description

technical field [0001] The invention belongs to the technical field of mechanical vibration testing, and in particular relates to an optical fiber grating acceleration sensor with adjustable sensitivity, which is especially suitable for monitoring the vertical vibration of floors caused by pedestrian loads in the health monitoring of assembled concrete structures. Background technique [0002] With the development of fiber grating sensing technology, fiber grating acceleration sensors have been widely used in health monitoring of civil engineering structures. Traditional electrical sensors mainly include magnetoelectric and inductive sensors. Among them, the biggest disadvantage of the magnetoelectric sensor is that the lower limit of the detectable vibration frequency is greater than 13Hz, so a specially designed correction circuit is required to reduce its detectable lower limit frequency. After calibration, the lowest measurable frequency is 0.6Hz. The normal walking fr...

AI Technical Summary

Problems solved by technology

[0003] Most of the fiber grating acceleration sensors currently researched are pasting the grating on the surface of the cantilever beam. When the mass block causes the cantilever beam to strain due to vibration, the refractive index and period of the fiber grating pasted on the surface of the cantilever beam will change, thereby making the fiber grating The Bragg reflection wavelength shift of

Images