scholarly journals Study of reliability of fibre Bragg grating fibre optic strain sensors for field-test applications

2012 ◽  
Vol 185 ◽  
pp. 8-16 ◽  
Author(s):  
Frederic Surre ◽  
Richard H. Scott ◽  
Pradipta Banerji ◽  
P.A.M. Basheer ◽  
Tong Sun ◽  
...  
Keyword(s):  
Field Test ◽  
Strain Sensors ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Fibre Optic

Leak detection on water pipelines in unsaturated ground by discrete fibre optic sensing

2019 ◽  
Vol 19 (4) ◽  
pp. 1219-1236 ◽  
Author(s):  
Schalk Willem Jacobsz ◽  
Sebastian Ingo Jahnke
Keyword(s):  
Unsaturated Soil ◽  
Ground Deformation ◽  
Bragg Gratings ◽  
Leak Detection ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Fibre Optic ◽  
Temperature Changes ◽  
Water Leak ◽  
Fibre Bragg Gratings

The article describes a study using discrete fibre optic sensing as a means of leak detection on water distribution pipes installed in unsaturated ground. A short length of pipe fitted with artificial leak points was installed, to which a fibre optic cable with fibre Bragg gratings was attached. An optical fibre with fibre Bragg gratings was also installed in the ground parallel to but separate from the pipe. Thermistors were installed at selected locations to measure temperature changes independent of strain. It was found that a simulated water leak resulted in clearly detectable temperature changes and thermally induced fibre Bragg grating wavelength changes in the ground around the pipe. However, significantly larger deformation-induced fibre Bragg grating wavelength changes were measured on the pipe walls and also in the initially unsaturated ground in response to leaks. A wetting front originating from a water leak propagating through unsaturated soil is associated with significant effective stress changes because the infiltrating water alters the ambient matric suction in the soil. This effective stress change is associated with significant ground deformation resulting in a fibre Bragg grating response which significantly exceeds the thermal response associated with (usually) colder water leaking into unsaturated soil. The study illustrates advantages of measuring ground deformation-induced fibre Bragg grating wavelength changes over pure temperature changes as an efficient means of leak detection in unsaturated ground. However, due to the limited number of fibre Bragg gratings that can be monitored along a single optical fibre, a leak detection system suitable for practical implementation should be based on distributed fibre optic strain sensing, an aspect requiring further research.

scholarly journals Fibre Bragg Grating Based Strain Sensors: Review of Technology and Applications

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3115 ◽  
Author(s):  
Carlo Campanella ◽  
Antonello Cuccovillo ◽  
Clarissa Campanella ◽  
Abdulkadir Yurt ◽  
Vittorio Passaro
Keyword(s):  
Research Field ◽  
Strain Sensors ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Mode Splitting ◽  
Key Sectors ◽  
Low Costs ◽  
And Performance ◽  
Physical Principles ◽  
Advanced Applications

Fibre Bragg grating (FBG) strain sensors are not only a very well-established research field, but they are also acquiring a bigger market share due to their sensitivity and low costs. In this paper we review FBG strain sensors with high focus on the underlying physical principles, the interrogation, and the read-out techniques. Particular emphasis is given to recent advances in highly-performing, single head FBG, a category FBG strain sensors belong to. Different sensing schemes are described, including FBG strain sensors based on mode splitting. Their operation principle and performance are reported and compared with the conventional architectures. In conclusion, some advanced applications and key sectors the global fibre-optic strain sensors market are envisaged, as well as the main market players acting in this field.

Design and testing of fibre Bragg grating force transducers for the measurement of pantograph–catenary contact force

2018 ◽  
Vol 233 (4) ◽  
pp. 396-409 ◽  
Author(s):  
Marco Bocciolone ◽  
Giuseppe Bucca ◽  
Andrea Collina ◽  
Lorenzo Comolli
Keyword(s):  
Contact Force ◽  
Force Measurement ◽  
Force Transducer ◽  
Optical Force ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Fibre Optic ◽  
Design Development ◽  
Force Transducers ◽  
Set Up

This paper deals with the design, development and testing of a novel force transducer based on fibre-optic technology, for the measurement of contact force between a pantograph and an overhead line. Due to the particular application, in which part of the measurement chain is at high voltage and part is at ground potential, fibre-optic technology has the advantage of making the set-up easier to install and to manage with respect to the adoption of classical electrical-based transducers. Fibre Bragg grating is used as detectors in strain-based force transducers developed for this purpose. Considering that the force transducers become part of the connection between each collector of the pan head and the suspension, a proper design matching many conflicting requirements, such as encumbrance, mass, static and fatigue strength and sensitivity, is necessary. Laboratory tests and in-line tests proved the suitability of the optical force transducers. In particular, tests demonstrated that optical transducers represent an alternative to the classical electrical-based transducers for pantograph–catenary force measurement, reducing the complexity of the complete measurement set-up.

scholarly journals Field monitoring of static, dynamic, and statnamic pile loading tests using fibre Bragg grating strain sensors

2009 ◽  
Author(s):  
Jin Li ◽  
Ricardo P. Correia ◽  
Edmon Chehura ◽  
Stephen Staines ◽  
Stephen W. James ◽  
...  
Keyword(s):  
Field Monitoring ◽  
Strain Sensors ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Loading Tests

Demultiplexing of fibre Bragg grating temperature and strain sensors

1994 ◽  
Vol 111 (1-2) ◽  
pp. 51-54 ◽  
Author(s):  
G.P. Brady ◽  
S. Hope ◽  
A.B.Lobo Ribeiro ◽  
D.J. Webb ◽  
L. Reekie ◽  
...  
Keyword(s):  
Strain Sensors ◽  
Bragg Grating ◽  
Fibre Bragg Grating
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