scholarly journals Distributed Optical Fiber-Based Approach for Soil–Structure Interaction

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 321 ◽  
Author(s):  
Nissrine Boujia ◽  
Franziska Schmidt ◽  
Christophe Chevalier ◽  
Dominique Siegert ◽  
Damien Pham Van Bang
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Lateral Loads ◽  
Dynamic Tests ◽  
Strain Measurements ◽  
Winkler Model ◽  
Optical Frequency Domain Reflectometry ◽  
Frequency Domain Reflectometry ◽  
The Stability ◽  
Distributed Optical Fiber

Scour is a hydraulic risk threatening the stability of bridges in fluvial and coastal areas. Therefore, developing permanent and real-time monitoring techniques is crucial. Recent advances in strain measurements using fiber optic sensors allow new opportunities for scour monitoring. In this study, the innovative optical frequency domain reflectometry (OFDR) was used to evaluate the effect of scour by performing distributed strain measurements along a rod under static lateral loads. An analytical analysis based on the Winkler model of the soil was carefully established and used to evaluate the accuracy of the fiber optic sensors and helped interpret the measurements results. Dynamic tests were also performed and results from static and dynamic tests were compared using an equivalent cantilever model.

J044021 Strain Measurements inside Bonded Layer by Distributed Fiber-Optic Sensors

2011 ◽  
Vol 2011 (0) ◽  
pp. _J044021-1-_J044021-3
Author(s):  
Hideaki MURAYAMA ◽  
Kazuro KAGEYAMA ◽  
Hirotaka IGAWA
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Strain Measurements

scholarly journals Local and Global Approaches for Damage Detection in Composite Structures by Fiber Optic Sensors

2018 ◽  
Author(s):  
Alfredo Guemes ◽  
Antonio Fernandez- Lopez ◽  
Patricia F. Diaz-Maroto ◽  
Angel Lozano ◽  
Julián Sierra-Pérez
Keyword(s):  
Damage Detection ◽  
Composite Structures ◽  
Fiber Optic ◽  
A Priori ◽  
Fiber Optic Sensors ◽  
Network Density ◽  
Strain Measurements ◽  
Damage Location ◽  
Local Technique ◽  
External Loads

Fiber optic sensors cannot measure damage; for getting information about damage from strain measurements, additional strategies are needed, and several alternatives have been proposed. This paper discuss two independent concepts: the first one is based on detecting the new strains appearing around a damage spot; the structure does not need to be under loads; the technique is very robust, damage detectability is high, but it requires sensors to be located very close to the damage, so it is a local technique. The second approach offers a wider coverage of the structure, it is based on identifying the changes caused by the damage on the strains field in the whole structure for similar external loads. Damage location does not need to be known a priori, detectability is dependent upon the sensors network density, damage size and the external loads. Examples of application to real structures are given.

scholarly journals Enhancement of Distributed Temperature Sensitivity Using Al-Coated Fiber in OFDR

2018 ◽  
Author(s):  
Yong-seok Kwon ◽  
Khurram Naeem ◽  
Min Yong Jeon ◽  
Il-Bum Kwon
Keyword(s):  
Temperature Sensitivity ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Coated Fiber ◽  
Rayleigh Backscattering ◽  
Enhanced Sensitivity ◽  
Optical Frequency Domain Reflectometry ◽  
Frequency Domain Reflectometry ◽  
Distributed Measurement ◽  
Distributed Optical Fiber

We present a distributed optical-fiber temperature sensor with enhanced sensitivity based on an Al-coated fiber using the Rayleigh backscattering spectra (RBS) shift in optical frequency-domain reflectometry (OFDR). The Al-coated sensing fiber with a higher thermal expansion coefficient compared to silica produces a strain-coupled shift in the RBS under an increase in temperature. This effect leads to an enhanced temperature sensitivity of the distributed measurement scheme. Our results revealed that the temperature sensitivity obtained using the Al-coated fiber in OFDR was ~56% higher relative to that of a single-mode fiber. Moreover, the minimum measurable temperature recorded was 1 °C with a spatial resolution of 5 cm.

Optical frequency domain reflectometry: principles and applications in fiber optic sensing

2016 ◽  
Author(s):  
Stephen T. Kreger ◽  
Nur Aida Abdul Rahim ◽  
Naman Garg ◽  
Sandra M. Klute ◽  
Daniel R. Metrey ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Fiber Optic ◽  
Optical Frequency ◽  
Optical Frequency Domain Reflectometry ◽  
Frequency Domain Reflectometry ◽  
Fiber Optic Sensing
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