The Development and the Use of Fiber Optic Sensors for the Structural Health Monitoring of Composite (GFRP) Structures

2002 ◽  
Author(s):  
Evageline Rivera ◽  
Dimos Polyzois ◽  
Douglas J. Thomson ◽  
Ningguang Xu
Keyword(s):  
Structural Integrity ◽  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Sensor Technology ◽  
Promising Alternative ◽  
Interferometric Sensors ◽  
Optic Sensor ◽  
Composite Glass ◽  
Path Lengths

The development of a fiber optic sensor system for the long-term monitoring of composite glass fiber-reinforced polymer (GFRP) poles will be presented. There is a growing interest in developing techniques for evaluating and monitoring their structural integrity. In the past few years, fiber optic sensor technology has emerged as a promising alternative to conventional methods of monitoring such as strain gauges. Fiber optic sensors can be attached to or embedded in civil structures such as bridges, dams and buildings. They operate by responding to changes in temperature and strain on the structure. The long gauge fiber optic sensor measures the average strain between two points on a structure. Long gauges are interferometric sensors that involve phase matching two optical paths to create a maximum interference pattern at the photodetector. The strain is calculated using the distance in which the reference arm of the interferometer is moved in order to match the optical path lengths.

An improving demodulation of interferometric fiber optic sensor technology

2013 ◽  
Author(s):  
Li Gao ◽  
Yong Li ◽  
Zhaorui Chu ◽  
Ming Wu ◽  
Nan Lin
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Sensor Technology ◽  
Optic Sensor

scholarly journals Multifunctional Extrinsic Fiber Optic Sensor to Measure Various Parameters of Liquids at the Operating Wavelength of 660nm Employing a U-Shaped Glass Rod as a Sensing Element

2019 ◽  
Vol 8 (2S3) ◽  
pp. 1418-1431
Keyword(s):  
Optical Fibers ◽  
Fiber Optic ◽  
Adiabatic Compressibility ◽  
Molar Refraction ◽  
Fiber Optic Sensor ◽  
Sensor Technology ◽  
Sensing Element ◽  
Optic Sensor ◽  
Operating Wavelength ◽  
Shaped Glass

Fiber Optic sensor technology has become more popular since early 1970’s during which the mechanism of losses from optical fibers was exploited to construct a new class of fiber optic sensors and systems. A novel fiber optic sensor has been developed by connecting a U-shaped glass element of specific dimensions between a light source of 660nm wavelength and an optical power detector by using a couple of PCS optical fibers of 200/230μm diameters of core and cladding respectively. The sensor can be employed to measure several parameters such as Refractive Index, Density, Viscosity, Ultrasonic Velocity, Molar Volume, Molar Refraction, Dielectric Constant, Acoustic Impendence, Adiabatic Compressibility, Viscous Relaxation Time, Intermolecular Free Length, Absorption Coefficient, Gibb’s Free Energy, Free Volume, Internal Pressure and their excess parameters of Toluene and tert-Butanol mixtures at 30℃ temperature and at the operating wavelength of 660nm

scholarly journals Questions of application of fiber-optic sensors for monitoring crack growth during rock deformations

2021 ◽  
Vol 2140 (1) ◽  
pp. 012037
Author(s):  
V V Yugay ◽  
P Sh Madi ◽  
S B Ozhigina ◽  
D A Gorokhov ◽  
A D Alkina
Keyword(s):  
Optical Fiber ◽  
Fiber Optic ◽  
Single Mode ◽  
Mechanical Action ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Mountain Range ◽  
Mining Equipment ◽  
Optic Sensor ◽  
Rock Deformations

Abstract The paper considers ways to solve the problem of developing a system for monitoring displacement in quarries, which are the main main cause of the collapse of boards and berms in quarries. To ensure safety and constant monitoring during work at the quarry, there are chiseled fiber-optic sensors. The fiber-optic sensor is made on the basis of a single-mode optical fiber, which makes it possible to measure the displacements of the mountain range at distances of about 30 km with high accuracy. Laboratory sample a fiber-optic sensor in its work uses a method for monitoring additional losses that occur during mechanical action on an optical fiber. The fiber-optic sensor was made to show a fairly high linearity and accuracy during measurements and can be used to control the deformation of the array after appropriate refinement of its design. This article is aimed at creating means of controlling the process of deformation and displacement of a mountain massif. Ultimately, the results of the study will help prevent accidents associated with the collapse of the sides. Since the growth of cracks in the rocks of the bort mountain massif leads to its sudden collapse and creates a significant danger for personnel, it also causes the failure of mining equipment.

Low-cost real-time fiber optic sensor for intrusion detection

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adel Abdallah ◽  
Mohamed M. Fouad ◽  
Hesham N. Ahmed
Keyword(s):  
Signal Processing ◽  
Intrusion Detection ◽  
Real Time ◽  
Fiber Optic ◽  
Reference Signal ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Content Type ◽  
Intensity Modulated ◽  
Optic Sensor

Purpose The purpose of this paper is to introduce a novel intensity-modulated fiber optic sensor for real-time intrusion detection using a fiber-optic microbend sensor and an optical time-domain reflectometer (OTDR). Design/methodology/approach The proposed system is tested using different scenarios using person/car as intruders. Experiments are conducted in the lab and in the field. In the beginning, the OTDR trace is obtained and recorded as a reference signal without intrusion events. The second step is to capture the OTDR trace with intrusion events in one or multiple sectors. This measured signal is then compared to the reference signal and processed by matrix laboratory to determine the intruded sector. Information of the intrusion is displayed on an interactive screen implemented by Visual basic. The deformer is designed and implemented using SOLIDWORKS three-dimensional computer aided design Software. Findings The system is tested for intrusions by performing two experiments. The first experiment is performed for both persons (>50 kg) in the lab and cars in an open field with a car moving at 60 km/h using two optical fiber sectors of lengths 200 and 500 m. For test purposes, the deformer length used in the experiment is 2 m. The used signal processing technique in the first experiment has some limitations and its accuracy is 70% after measuring and recording 100 observations. To overcome these limitations, a second experiment with another technique of signal processing is performed. Research limitations/implications The system can perfectly display consecutive intrusions of the sectors, but in case of simultaneous intrusions of different sectors, which is difficult to take place in real situations, there will be the ambiguity of the number of intruders and the intruded sector. This will be addressed in future work. Suitable and stable laser power is required to get a suitable level of backscattered power. Optimization of the deformer is required to enhance the sensitivity and reliability of the sensor. Practical implications The proposed work enables us to benefit from the ease of implementation and the reduced cost of the intensity-modulated fiber optic sensors because it overcomes the constraints that prevent using the intensity-modulated fiber optic sensors for intrusion detection. Originality/value The proposed system is the first time long-range intensity-modulated fiber optic sensor for intrusion detection.

Fiber Optic Sensors for Monitoring Pipe Bending Due to Ground Movement

2006 ◽  
Author(s):  
Sam Cauchi ◽  
Thierry Cherpillod ◽  
Don Morison ◽  
Ed McClarty
Keyword(s):  
Fiber Optic ◽  
Monitoring Program ◽  
Fiber Optic Sensors ◽  
Ground Movement ◽  
Fiber Optic Sensor ◽  
Optic Sensor ◽  
Coiled Fiber ◽  
Back Filling ◽  
Pipe Bending ◽  
Sour Gas

This paper describes an installation of fiber optic sensors designed to measure pipe bending due to ground movement at three sites on a 16” gas transmission line. The sour gas pipeline had failed in December, 2004 from excessive forces related to ground movement. As temporary mitigation the pipeline was daylighted to reduce the soil traction forces but a comprehensive monitoring program had to be developed before placing the pipeline back into conventional service. During the time when the section of pipeline was daylighted, three linear and three coiled fiber optic sensors were installed at each of three sites selected as part of a system designed to measure bending strains in the 0.01–1.0% range. The two types of sensors were placed in pairs approximately at the 12, 4, and 8 o’clock positions. Conventional vibrating wire (VW) strain gauges were also installed at the fiber optic sensor locations for comparison purposes. Slope inclinometers were installed at each of the instrumentation sites to correlate ground movement to pipe bending. Following pipeline re-coating, and back-filling, visits to the site were made at approximately monthly intervals to gather data at conveniently placed break-out boxes. The complete fiber optic sensor system functionality is described and results are presented that show how the raw strain data are transformed into bending using software that also serves as a secure database.

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