Application of Packaging Technique in Fiber Bragg Grating Temperature Sensor for Measuring Localized and Nonuniform Temperature Distribution

2013 ◽  
Vol 64 (3) ◽  
Author(s):  
Liau Qian Yu ◽  
Asrul Izam Azmi ◽  
Siti Musliha Aishah Musa ◽  
Raja Kamarulzaman Raja Ibrahim

The development of Fiber Bragg Grating (FBG) sensing technique has improved significantly especially in the sensor head design and real-time data acquisition technique. This paper presents the development of a simple and cost effective packaging technique that further enhances the performances of the FBG sensor. The packaged FBG sensor overcomes the nonuniform heat distribution of a bare FBG that causes eccentric response of FBG spectrum. Therefore, the packaged FBG sensor could be operated for a localized area with high temperature differential. The packaging also compensates the unwanted strain effect from the surrounding which makes temperature measurement become more accurate. The experimental works have been successfully carried out to demonstrate the system operation and the packaging functionalities. The temperature sensitivity coefficient of the bare FBG sensor measured in experiment is 10.05 pm/°C, while the packaged fiber sensor is 10.09 pm/°C, which are expected from the design.

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.


Author(s):  
Ruiqi Ma ◽  
Guoqing Feng ◽  
Huilong Ren ◽  
Peng Fu ◽  
Shuang Wu ◽  
...  

Hull monitoring system with Fiber Bragg Grating (FBG) sensors increasingly receives people’s attentions. However, for the ship hull monitoring, the deformation of hull girder changes a lot as is subjected to a huge temperature variation. Therefore, the compensation method with only FBG temperature self-correction is not suitable for the hull monitoring sensors because no material thermal expansion effects are reasonably included. In this paper, the new compensation method of hull monitoring FBG sensor based on the sensor theory with both FBG temperature self-correction and steel thermal expansion effects correction is studied. The coupled compensation method suitable for hull monitoring sensor is obtained by theoretical derivation. As the comparison, the coupled compensation experiment was carried out. The results show that the relative error under the temperature compensation method is large in the case of drastic strain and temperature changes, and the correction results of the tested method will be closer to the true level.


2012 ◽  
Vol 485 ◽  
pp. 526-531 ◽  
Author(s):  
Hui Juan Dong ◽  
Yong Cai ◽  
Jun He ◽  
Ren Bing Liu

A novel fiber Bragg grating vortex flowmeter was designed in this work, where the Bragg grating was enfolded in a cylinder eddy generator. Bragg grating subject to force and the corresponding strain were analyzed. Subsequently, the relationships between grating’s axial strain and flow were developed. In order to improve the flowmeter's resolution, the system was simplified by a mass-spring-damper model, which was used to analyze resonance and choose acrylic glass as cylinder's material. In terms of the resolution of FBG sensor demodulation device and factors of vortex's formation, the measuring range of flowmeter is 1200L/h~5000L/h. The resolution is less than 40L/h with flow exceeding 2000L/h. The damping ratio is not sensitive to the flow when it is less than 2000L/h.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 770
Author(s):  
Konrad Markowski ◽  
Kacper Wojakowski ◽  
Ernest Pokropek ◽  
Michał Marzęcki

In this article, an extensive analysis of the performance of the fiber optics-based abrasion sensor that utilizes chirped fiber Bragg grating, is presented. For the response investigation during abrasion, a numerical analysis, based on the transfer matrix method and coupled mode theory, is provided. The influence of the SLED source spectral position in respect to the spectral position of the chirped fiber Bragg grating is evaluated together with the influence of the changes of the ambient temperature of the sensor. Experimental verification of the sensor’s performance is provided, together with the proposition of the packaging of the sensor. In the article, a simple, cost-effective and multiplexation-ready concept of the wear or abrasion sensor system is presented and discussed.


2013 ◽  
Vol 303-306 ◽  
pp. 67-73 ◽  
Author(s):  
Yan An Zhang ◽  
Zheng Liu ◽  
Lin Yong Shen ◽  
Jin Wu Qian

In trenchless detection of underground pipelines, a method has been introduced which employs Fiber Bragg Grating (FBG) sensors to detect curvatures of the pipeline at discrete points and reconstructs the spatial trajectory of the pipeline by means of a newly developed approach. In measuring the pipeline curvature, the FBG sensor may be twisted besides sustaining bending deformation. This paper proposes a new algorithm for curvature calculation at discrete points, considering both overall revolving and partial twisting of the FBG sensors in order to enhance the curve fitting accuracy. Simulation results verify the effectiveness of the method.


2019 ◽  
Vol 14 (12) ◽  
pp. 1725-1732
Author(s):  
Xingyu Zheng

With the prolongation of the service life of spacecraft, the structural failure of spacecraft caused by air resistance and aging poses a direct threat to the safe operation of spacecraft. The structural failure of aircraft is concerned by many researchers. Among them, the fiber Bragg grating (FBG) sensor has become a hotspot of aircraft structural fault research because of its good performance. Facing the difficulties of structural fault location of traditional spacecraft, slow data updating speed and poor transplant ability of positioning device, a structural fault angle measurement model based on FBG strain flower is constructed by combining FBG sensor with the principle of right-angle strain flower. On the problem of determining the main strain orientation, two groups of FBG strain rosette locations are selected to determine, and different groups of locations are cross-solved to obtain the original coordinates of impact. At the same time, aiming at the structural problems of four simple thin plates in the aircraft, a method of judging the structural load based on the disturbance trend is proposed. In the process of experiment, it is necessary to test the positioning accuracy of the structure obtained by the sensor and the size error of the load. In order to better simulate the real scene, a simulation platform of aircraft structure impact is built. During the testing process, it is found that the sensor detection platform proposed in this study can locate structural faults within 2.8 cm. The average time required for location judgment is about 1.7 ms, and the error of structural impact force is about 2.86 N. Through this study, a new detection method for structural fault detection of spacecraft is proposed, which can better ensure the safety of spacecraft.


2011 ◽  
Vol 97-98 ◽  
pp. 301-304 ◽  
Author(s):  
Ke Li ◽  
Jian Guang Xie

Based on the fiber Bragg grating sensing technology, a FBG sensor is designed to monitor the dynamic response of asphalt concrete; the sensitivity coefficient of FBG sensor is 1.28pm/με. Through the static load test, the correlation between strain and wavelength variation is 0.1797µε/pm, after second packaged and embedded in SMA-13 asphalt concrete. The instantaneous impact on the road of high-speed vehicles is simulated by using drop hammer. The results are shown that the Sensor can satisfy the requirements of practical applications and succeed in monitoring the dynamic response of asphalt concrete. The monitored signal can reflect the viscoelastic-plastic deformation law of asphalt concrete. The sensor can be used to monitor the dynamic response of asphalt concrete.


2014 ◽  
Vol 487 ◽  
pp. 517-521
Author(s):  
Yue Ming Liu ◽  
Zhong Cheng Xia ◽  
Xiao Liang Gao

Pressure pipelines have been applied widely in the chemical industry, the petroleum enterprises and the electrical power plants. Leakage and explosion accidents happened frequently owing to the weakness of the pressure pipeline. To monitoring the pressure pipeline weakness, a novel method is presented by using optical FBG (FBG: Fiber Bragg Grating) sensors to carry on the real-time monitoring of the pressure piping surface strains. A typical pressure pipeline was fabricated with weak position of L shaped, Tee shaped and U shaped joints. The strains of the weak position were analyzed by the ANSYS software, and then the same weak positions were monitored by experimental method of FBG sensor. The FBG sensor was verified a feasible means to monitoring the pressure pipeline by comparing the ANSYS software results with the experimental results of FBG sensors.


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