Experiment and Research of Using Fiber Bragg Grating to Monitor the Dynamic Response of Asphalt Concrete

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.

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3395 ◽  
Author(s):  
Qi Wu ◽  
Yoji Okabe ◽  
Fengming Yu

The fiber Bragg grating (FBG) sensor, which was developed over recent decades, has been widely used to measure manifold static measurands in a variety of industrial sectors. Multiple experiments have demonstrated its ability in ultrasonic detection and its potential in ultrasonic structural health monitoring. Unlike static measurements, ultrasonic detection requires a higher sensitivity and broader bandwidth to ensure the fidelity of the ultrasonic Lamb wave that propagates in a plate-like structure for the subsequent waveform analysis. Thus, the FBG sensor head and its corresponding demodulation system need to be carefully designed, and other practical issues, such as the installation methods and data process methods, should also be properly addressed. In this review, the mature techniques of FBG-based ultrasonic sensors and their practical applications in ultrasonic structural health monitoring are discussed. In addition, state-of-the-art techniques are introduced to fully present the current developments.


2014 ◽  
Vol 599-601 ◽  
pp. 1085-1089
Author(s):  
Mian Huang ◽  
Yong Hong Wu ◽  
Yuan Yu Guan ◽  
Ying Na Li ◽  
Tao Xie ◽  
...  

Reinforced concrete piles are used when structures are constructed on soft ground, because it is necessary to transfer the loads into deeper strata with a sufficient bearing capacity. With the purpose of receiving more precise information about the pile features, four fiber Bragg grating strain sensors are embedded at different levels of the pile to measure the strain distribution during straining and pull-out tests. Test Pile vertical uplift static load test results show that, settlement of the test pile is steep variations, the steep rise starting point corresponding to the load of 3300 kN for the Uplift Ultimate Bearing capacity, the corresponding uplift amount is 12.45 mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 115 με, 42 με, 6 με and-3 με. Maximum loading capacity is 3600 kN, the corresponding uplift amount is 30.13mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 142 με, 61 με, 7 με and-1 με.


Author(s):  
M. L. Filograno ◽  
A. Rodri´guez-Barrios ◽  
M. Gonza´lez-Herraez ◽  
P. Corredera ◽  
S. Marti´n-Lo´pez ◽  
...  

In this work we present field tests concerning the application of Fiber Bragg Grating (FBG) sensors for the monitoring of railway traffic. The test campaigns are performed on the Spanish high speed line Madrid–Barcelona, with different types of trains (S-102 TALGO–BOMBARDIER, S-103 SIEMENS-VELARO and S-120 CAF). We located the FBG sensors in the rail track at 70 km from Madrid in the country side, where the trains primarily are tested during commercial operation with maximum speeds between 250–300 km/h. The FBG sensor interrogation system used allows the simultaneous monitoring of four FBG sensors at 8000 samples/s. The different position of the FBG sensors in relation with the rail can be used with different purposes such as train identification, axle counting, speed and acceleration detection, wheel imperfections monitoring and dynamic load calculation.


2013 ◽  
Vol 562-565 ◽  
pp. 1346-1352
Author(s):  
Jun Jie Bai ◽  
Jian Xing Li ◽  
Jun Zhang ◽  
Xiao Yun Zhang ◽  
Le Wang ◽  
...  

The real-time monitoring technologies of smart civil structure based on detecting picometer-scale wavelength shift of fiber Bragg grating (FBG), including the wavelength demodulation technology of FBG, are researched extensively at home and abroad. In the paper, using the technologies of wavelength division multiplex (WDM) and time division multiplex (TDM), fiber Bragg grating (FBG) sensor network was built for monitoring smart structure health condition. Based on SOPC (System on Programmable Chip) technology and fiber comb filter, a high-speed and high-precision wavelength demodulation scheme of FBG sensor network was proposed. The optical system and hardware circuit for demodulation system were designed specifically. To improve the accuracy of demodulation system of FBG, a constant temperature channel of the demodulation system connected with a fiber comb filter, which offered reference points to calibrate the Bragg grating center wavelength. Based on 32-bit soft-core processor NoisⅡ, the embedded system collected and processed the photoelectric signal voltage transformed to rectangular voltage pulse. The upper computer displayed dynamically the FBG wavelength demodulation process and calibrated the Bragg grating center wavelength. The experiments of FBG wavelength demodulation and health monitoring of smart structural embedded fiber Bragg gratings were done. Experimental results show that, the FBG wavelength demodulation method can be used to demodulate the FBG wavelength with high speed and high precision (± 2 pm), which can be used extensively in large-scale multipoint monitor engineering, and the strains of the smart structure can be measured accurately.


2018 ◽  
Vol 536 ◽  
pp. 847-849 ◽  
Author(s):  
Akihiko Ikeda ◽  
Toshihiro Nomura ◽  
Yasuhiro H. Matsuda ◽  
Shuntaro Tani ◽  
Yohei Kobayashi ◽  
...  

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.


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.


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