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Optical Fiber Sensors for Aircraft Structural Health Monitoring.

García I, Zubia J, Durana G, Aldabaldetreku G, Illarramendi MA, Villatoro J - Sensors (Basel) (2015)

Bottom Line: Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors.Several practical applications for structures and engines we have been working on are reported in this article.With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

View Article: PubMed Central - PubMed

Affiliation: Department of Communications Engineering, E.T.S.I. of Bilbao, University of the Basque Country UPV/EHU, Alda. Urquijo s/n Bilbao 48013, Spain. iker.garciae@ehu.eus.

ABSTRACT
Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

No MeSH data available.


Related in: MedlinePlus

FBG concept and working principle.
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sensors-15-15494-f001: FBG concept and working principle.

Mentions: An optical fiber grating can be defined as a periodic perturbation pattern in the refractive index of the fiber core, in such a way that certain wavelengths of the guided mode are diffracted either into other radiation modes or into cladding modes [26]. In the former case, the device is known as a short-period fiber grating or fiber Bragg grating. Such gratings have a sub-micron period and a total length ranging from 1 mm to 10 mm. A Bragg grating allows most of the power (Po) to propagate forward. However, when the guided mode in a single-mode fiber reaches the grating, a certain portion of its incident power (Pi) is reflected at each grating plane. The electric fields are added up only if the Bragg condition given by Equation (1) is satisfied: (1)λB=2⋅neff⋅Λ where λB is the resonant wavelength or Bragg wavelength, neff is the effective index of the mode and Λ is the grating period. The working principle of the FBGs is illustrated in Figure 1.


Optical Fiber Sensors for Aircraft Structural Health Monitoring.

García I, Zubia J, Durana G, Aldabaldetreku G, Illarramendi MA, Villatoro J - Sensors (Basel) (2015)

FBG concept and working principle.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541841&req=5

sensors-15-15494-f001: FBG concept and working principle.
Mentions: An optical fiber grating can be defined as a periodic perturbation pattern in the refractive index of the fiber core, in such a way that certain wavelengths of the guided mode are diffracted either into other radiation modes or into cladding modes [26]. In the former case, the device is known as a short-period fiber grating or fiber Bragg grating. Such gratings have a sub-micron period and a total length ranging from 1 mm to 10 mm. A Bragg grating allows most of the power (Po) to propagate forward. However, when the guided mode in a single-mode fiber reaches the grating, a certain portion of its incident power (Pi) is reflected at each grating plane. The electric fields are added up only if the Bragg condition given by Equation (1) is satisfied: (1)λB=2⋅neff⋅Λ where λB is the resonant wavelength or Bragg wavelength, neff is the effective index of the mode and Λ is the grating period. The working principle of the FBGs is illustrated in Figure 1.

Bottom Line: Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors.Several practical applications for structures and engines we have been working on are reported in this article.With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

View Article: PubMed Central - PubMed

Affiliation: Department of Communications Engineering, E.T.S.I. of Bilbao, University of the Basque Country UPV/EHU, Alda. Urquijo s/n Bilbao 48013, Spain. iker.garciae@ehu.eus.

ABSTRACT
Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

No MeSH data available.


Related in: MedlinePlus