Multi-scale load identification system based on distributed optical fiber and local FBG-based vibration sensors

Optik ◽  
2020 ◽  
Vol 219 ◽  
pp. 165159 ◽  
Author(s):  
Shihai Zhang ◽  
Jianping He ◽  
Quanfu Yu ◽  
Xianshun Wu
Keyword(s):  
Optical Fiber ◽  
Identification System ◽  
Load Identification ◽  
Multi Scale ◽  
Vibration Sensors ◽  
Distributed Optical Fiber

Moving Load Identification of Small and Medium-Sized Bridges Based on Distributed Optical Fiber Sensing

2016 ◽  
Vol 16 (04) ◽  
pp. 1640021 ◽  
Author(s):  
Cai Qian Yang ◽  
Dan Yang ◽  
Yi He ◽  
Zhi Shen Wu ◽  
Ye Fei Xia ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Moving Load ◽  
Vehicle Speed ◽  
Load Identification ◽  
Structure Response ◽  
Fiber Sensing ◽  
Optical Fiber Sensing ◽  
Fbg Sensors ◽  
Distributed Optical Fiber ◽  
Moving Load Identification

A novel method was proposed for the moving load identification of bridges based on the influence line theory and distributed optical fiber sensing technique. The method of load and vehicle speed identification was firstly theoretically studied, and then numerical simulation was also performed to study its accuracy and robustness. The numerical results showed that this method was characterized by high accuracy and excellent resistance to noise. Finally, the load identification of an actual continuous pre-stressed concrete beam bridge was carried out with the proposed method. The bridge consists of four pre-stressed box beams. At the same time, a weigh-in-motion system was also installed about 200 m in front of the bridge to measure the speed and moving loads with a purpose of comparing the load identification of the proposed method. Long gauge fiber Bragg grating (FBG) sensors with a gauge length of 1.0 m were adhered to the bottom of the beams. The individual loaded vehicles and the corresponding structure response were mainly monitored as standard samples, and the speed and weight of the sample vehicles were monitored and identified with the proposed method. The results revealed that the distributed long gauge FBG sensors were capable of sensing the structure response precisely and identifying the traffic load. On the basis of the design information and ambient vibration testing results, a refined model was established and the response under unit moving load was acquired for load identification. It was also shown that the sensors in different positions can achieve accurate vehicle speed and weight, the relative error of which are within 10% and 15%, respectively.

Distributed optical fiber vibration sensors based on unbalanced Michelson interferometer and PGC demodulation

2020 ◽  
Author(s):  
Zhihua Yu ◽  
Abdi Karim A. Dahir ◽  
Haolong Dai ◽  
Yuansheng Luo ◽  
Guang Qi ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Michelson Interferometer ◽  
Vibration Sensors ◽  
Distributed Optical Fiber

Multi-scale wavelet decomposition and its application in distributed optical fiber fences

2015 ◽  
Author(s):  
Huijuan Wu ◽  
Linqiang Zhang ◽  
Ya Qian ◽  
Hanyu Li ◽  
Weili Zhang ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Wavelet Decomposition ◽  
Multi Scale ◽  
Distributed Optical Fiber

scholarly journals Measurement Improvement of Distributed Optical Fiber Sensor via Lorenz Local Single Peak Fitting Algorithm

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1166
Author(s):  
Bin Liu ◽  
Jianping He ◽  
Shihai Zhang ◽  
Yinping Zhang ◽  
Jianan Yu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Frequency Shift ◽  
Optical Fiber Sensor ◽  
Gain Spectrum ◽  
Fiber Sensor ◽  
Peak Fitting ◽  
Fitting Algorithm ◽  
Distributed Optical Fiber Sensor ◽  
Brillouin Gain ◽  
Distributed Optical Fiber

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.

scholarly journals A Review of Recent Distributed Optical Fiber Sensors Applications for Civil Engineering Structural Health Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1818
Author(s):  
Mattia Francesco Bado ◽  
Joan R. Casas
Keyword(s):  
Structural Health Monitoring ◽  
Optical Fiber ◽  
Health Monitoring ◽  
Optical Fiber Sensors ◽  
Vibration Monitoring ◽  
Fiber Sensors ◽  
Structural Health ◽  
Comprehensive Collection ◽  
Monitoring Tools ◽  
Distributed Optical Fiber

The present work is a comprehensive collection of recently published research articles on Structural Health Monitoring (SHM) campaigns performed by means of Distributed Optical Fiber Sensors (DOFS). The latter are cutting-edge strain, temperature and vibration monitoring tools with a large potential pool, namely their minimal intrusiveness, accuracy, ease of deployment and more. Its most state-of-the-art feature, though, is the ability to perform measurements with very small spatial resolutions (as small as 0.63 mm). This review article intends to introduce, inform and advise the readers on various DOFS deployment methodologies for the assessment of the residual ability of a structure to continue serving its intended purpose. By collecting in a single place these recent efforts, advancements and findings, the authors intend to contribute to the goal of collective growth towards an efficient SHM. The current work is structured in a manner that allows for the single consultation of any specific DOFS application field, i.e., laboratory experimentation, the built environment (bridges, buildings, roads, etc.), geotechnical constructions, tunnels, pipelines and wind turbines. Beforehand, a brief section was constructed around the recent progress on the study of the strain transfer mechanisms occurring in the multi-layered sensing system inherent to any DOFS deployment (different kinds of fiber claddings, coatings and bonding adhesives). Finally, a section is also dedicated to ideas and concepts for those novel DOFS applications which may very well represent the future of SHM.

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