scholarly journals Fiber Bragg Grating Sensors-Based In Situ Monitoring and Safety Assessment of Loess Tunnel

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jinxing Lai ◽  
Junling Qiu ◽  
Haobo Fan ◽  
Qian Zhang ◽  
Zhinan Hu ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Wavelength Division Multiplexing ◽  
Electromagnetic Interference ◽  
Safety Assessment ◽  
Early Stage ◽  
Internal Force ◽  
In Situ Monitoring ◽  
Bragg Grating ◽  
Tunnel Structure

Compared with electrical strain gauges, fiber Bragg grating (FBG) sensing technology is a relatively novel method for tunnel structural health monitoring, which has a number of advantages including high accuracy, multiplexing, electromagnetic interference resistance, and good repeatability. In order to study the internal force of the tunnel liner and detect the potential safety hazards, series of strain monitoring tests of a loess tunnel, taking into account the complex stress and strain variation of the loess during tunnelling, were performed by employing the tandem linear FBG sensor arrays controlled by the wavelength division multiplexing (WDM) technology. The concrete strain has obvious linear characteristics over time in the early stage and then gradually tends to a stable value. Moreover, after the necessary temperature compensation, loess tunnel structure safety was assessed through the analysis of real-time strain and internal force of the liner concrete, and the FBG monitoring data and safety assessment results indicate that the safety factors of various liner sections all meet the code requirements, which verify the safety and stability of the tunnel liner structure. The FBG sensors-based in situ monitoring technology can be well applied in the loess tunnel structure safety assessment.

scholarly journals Corrigendum to “Fiber Bragg Grating Sensors-Based In Situ Monitoring and Safety Assessment of Loess Tunnel”

2019 ◽  
Vol 2019 ◽  
pp. 1-1 ◽  
Author(s):  
Jinxing Lai ◽  
Junling Qiu ◽  
Haobo Fan ◽  
Qian Zhang ◽  
Zhinan Hu ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Safety Assessment ◽  
In Situ Monitoring ◽  
Bragg Grating ◽  
Fiber Bragg Grating Sensors

scholarly journals In situ monitoring of photostriction in chalcogenide glass film using fiber Bragg grating sensors

2017 ◽  
Vol 11 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Sivakumar Gayathri ◽  
G. Sreevidya Varma ◽  
Gagandeep Singh ◽  
Bannur Nanjunda Shivananju ◽  
S. Sridevi ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Chalcogenide Glass ◽  
In Situ Monitoring ◽  
Bragg Grating ◽  
Glass Film ◽  
Fiber Bragg Grating Sensors

Damage localization with fiber Bragg grating Lamb wave sensing through adaptive phased array imaging

2018 ◽  
Vol 18 (1) ◽  
pp. 334-344 ◽  
Author(s):  
Zhenhua Tian ◽  
Lingyu Yu ◽  
Xiaoyi Sun ◽  
Bin Lin
Keyword(s):  
Fiber Bragg Grating ◽  
Electromagnetic Interference ◽  
Lamb Wave ◽  
Phased Array ◽  
Minimum Variance ◽  
Bragg Grating ◽  
Damage Localization ◽  
Weighting Factors ◽  
Wave Imaging ◽  
Grating Array

Fiber Bragg gratings are known being immune to electromagnetic interference and emerging as Lamb wave sensors for structural health monitoring of plate-like structures. However, their application for damage localization in large areas has been limited by their direction-dependent sensor factor. This article addresses such a challenge and presents a robust damage localization method for fiber Bragg grating Lamb wave sensing through the implementation of adaptive phased array algorithms. A compact linear fiber Bragg grating phased array is configured by uniformly distributing the fiber Bragg grating sensors along a straight line and axially in parallel to each other. The Lamb wave imaging is then performed by phased array algorithms without weighting factors (conventional delay-and-sum) and with adaptive weighting factors (minimum variance). The properties of both imaging algorithms, as well as the effects of fiber Bragg grating’s direction-dependent sensor factor, are characterized, analyzed, and compared in details. The results show that this compact fiber Bragg grating array can precisely locate damage in plates, while the comparisons show that the minimum variance method has a better imaging resolution than that of the delay-and-sum method and is barely affected by fiber Bragg grating’s direction-dependent sensor factor. Laboratory tests are also performed with a four–fiber Bragg grating array to detect simulated defects at different directions. Both delay-and-sum and minimum variance methods can successfully locate defects at different positions, and their results are consistent with analytical predictions.

Spectrum-profile-identification-based wavelength division multiplexing method for a fiber Bragg grating sensor

2017 ◽  
Vol 15 (7) ◽  
pp. 070605
Author(s):  
Yuheng Pan Yuheng Pan ◽  
Junfeng Jiang Junfeng Jiang ◽  
Weijia Lu Weijia Lu ◽  
Huijia Yang Huijia Yang ◽  
Kun Liu Kun Liu ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Wavelength Division Multiplexing ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Wavelength Division ◽  
Bragg Grating Sensor

Fiber Bragg grating sensors for in-situ temperature measurement on bending a flexible planar supercapacitor

2020 ◽  
Vol 314 ◽  
pp. 112266
Author(s):  
Ranjana Seema ◽  
Soumen Mandal ◽  
Preeti Singh ◽  
Souvik Paul ◽  
Nripen Chanda
Keyword(s):  
Temperature Measurement ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Fiber Bragg Grating Sensors

scholarly journals A Fiber Bragg Grating Based Torsional Vibration Sensor for Rotating Machinery

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2669 ◽  
Author(s):  
Jingjing Wang ◽  
Li Wei ◽  
Ruiya Li ◽  
Qin Liu ◽  
Lingling Yu
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Torsional Vibration ◽  
Electromagnetic Interference ◽  
Vibration Sensor ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Structural Parameter ◽  
Measurement Sensitivity ◽  
Fiber System

This paper proposes a new type of torsional vibration sensor based on fiber Bragg grating (FBG). The sensor has two mass ball optical fiber systems. The optical fiber is directly treated as an elastomer and a mass ball is fixed in the middle of the fiber in each mass ball fiber system, which is advantageously small, lightweight, and has anti-electromagnetic interference properties. The torsional vibration signal can be calculated by the four FBGs’ wavelength shifts, which are caused by mass balls. The difference in the two sets of mass ball optical fiber systems achieves anti-horizontal vibration and anti-temperature interference. The principle and model of the sensor, as well as numerical analysis and structural parameter design, are introduced. The experimental conclusions show that the minimum torsional natural frequency of the sensor is 27.35 Hz and the torsional vibration measurement sensitivity is 0.3603 pm/(rad/s2).

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