Seminar OnRole of FBG Sensors In Health Mointoring bridges

Railway

NARESH KUMAREnroll. No. 11593057

Introduction

In- Fibre Bragg grating (FBG) sensors have been subject to continuous and rapid development since they were first demonstrated for strain and temperature measurement.

1. The main reasons for this is because FBG sensors have a number of distinguishing advantages over other implementations of fibre optic sensors, including potentially low cost and unique wavelength-multiplexing capacity. The transduction mechanism is the modulation at the reflection wavelength of the sensing element.

2. The general aspects of the FBG sensors technology, including sensing principle, properties fabrication, interrogation and multiplexing technique, have been systematically reviewed by the author.

➔ Fiber Bragg Grating (FBG) is a periodic variation of the index of refraction in the core of an optical fiber.

● The reflection from the periodic structure will add up in phase when

which is the Bragg condition.

● Fabrication➔ When fiber is exposed to a pair of interfering UV beams then we would obtain

an interference pattern.

➔ In region of constructive interference the refractive index increases.

➔ The period (width) of grating can be controlled by angle between interfering beams.

➔ Exposing a germanium doped silica fiber to the interference pattern formed between two UV beams leads to formation of periodic refractive index variation in the core of the fiber.

● Technology Advantages

➔ Multiplexing

➔ Multifunctionality

➔ Long transmission distance

➔ Electric isolation

➔ Signal integrity

➔ Long term stability

Disadvantages

1.High cost of maintenance

2.Skiilled labor

3. reduction of motion artefacts

Applications

1. Weight measurement

2. Strength of bridges

3. To avoid derailment

4. Wheel balancing

5. Health monitoring`

6. Taking care of bridges and buildings

LITERATURE REVIEWYear Author(s) Area of Study Conclusion(s)

2005 Berardis et al. Use of FBG sensors for weight in motion

Development of a WIM technique based on use of FBG sensors and with high weight resolution was demonstrated byuse of a small sizedto solve problems related toconstrains imposed by high speed traffic that could affect the performance of the system, such as installation beneathasphalt layer.

2005 TAM et al. Fiber Bragg Grating Sensors for Structural and Railway Applications

Two field trials using FBG sensor arrays for train speed measurement and for strain measurements on different locations (suspension cable, rocker and truss girders) of the TsingMa Bridge were performed successfully

2008 Zhang et al. A portable, multi-function weight-in-motion (WIM) sensor systembased on Fiber Bragg Grating (FBG) technology

These obtained experimental results show us a rough but complete weighing system to measure and analyze the data ofweight and size of vehicle in motion

2009 Ham et al. Continuous Measurement of InteractionForces between Wheel and Rail

The study suggests a new method for obtaining continuousmeasurements of the wheel load, lateral force, and derailmentcoefficient using the conventional intermittent method.

Year Author(s) Area of Study Conclusion(s)

2011 Kolakowski et al.

Weighing of trains in motion as a part of health monitoring system for a raiway bridge.

This paper presents numerical and experimental results of a WIM procedure, which is meant tobe a part of an integrated SHM system dedicated to railway truss bridges

2012 Sekua and akowski

Piezo-based weigh-in-motion system for the railway transport

This paper presents numerical and experimental results of a WIM procedure, which is meant tobe a part of an integrated SHM system dedicated to railway truss bridges

Year Author(s) Area of Study Conclusion(s)

Year Author(s) Area of Study Conclusion(s)

2014 Yuen Novel application of a fibre optic-based train weigh-in-motion system in railway

Installation architecture and data interpretation for trainvibration measurement and wheel loading measurementhave been developed. The findings can serve as referencefor future FBG railway usage

REFERENCES

1. S. Berardis, M. A. Caponerob, F. Fellia, F. Roccoa ‘Use of FBG sensors for weigh in motion’ (2005) Vol.5855

2. H.Y. TAM, S.Y. Liu, B.O. Guan, W.H. Chung, T.H.T Chan and L.K. Cheng“Fiber Bragg Grating Sensors for Structural and Railway Applications” (2005) Vol.5634

3. Hongtao Zhang, Zhanxiong Wei, Qiming Zhao, Liang Guan, Jilin Zou, Lingling Fan, Shangming Yang, Dongcao Song, Gregory Recine, Hong-Liang Cui “A portable, multi-function weight-in-motion (WIM) sensor system based on Fiber Bragg Grating (FBG) technology” (2008)Vol.7004

REFERENCES (contd.)

4. Young-Sam Ham, Dong-Hyong Lee, Seok-Jin Kwon, Won-Hee You and Taek-Yul Oh “Continuous Measurement of Interaction Forces between Wheel and Rail”(2009) Vol.10

5. P. Kołakowski, K. Sekuła, D. Sala, A. Świercz & A. Orłowska “ Weighing of trains in motion as a part of health monitoring system for a railway bridge”(2011)

6. Krzysztof Seku and Przemys Ko akowski “Piezo-based weigh-in-motion system for the railway transport”(2012) Vol.19

7. Ken K. Yuen “Novel application of a fibre optic-based train weigh-in-motion system in railway”(2014) vol.21

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