Loosening Monitoring of Bolted Joints Using Optical Fiber Bending Sensor for Aircraft Lug Assembly

2012 ◽  
Vol 225 ◽  
pp. 540-545
Author(s):  
Hye Jin Shin ◽  
Jung Ryul Lee ◽  
Chan Yik Park
Keyword(s):  
Optical Fiber ◽  
Human Life ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Bolted Joints ◽  
Sensor Nodes ◽  
Optical Time Domain Reflectometer ◽  
Critical Defect ◽  
Optical Time ◽  
Bending Sensor

Bolted joints of aircraft lug assembly play an important role in connecting the wing and fuselage of an aircraft structure. Generally, the bolted joints get loosened because they are frequently exposed to the dynamic loads induced when an aircraft is in service. For this reason, it is important to monitor the condition of the bolted joints to avoid any critical defect that will lead to any risk in human life. However, it is difficult to conduct the bolted joints’ loosening inspection by an operator. In past few decades, optical fiber based sensor has been widely used due to its advancement over a conventional piezoelectric (PZT) sensor, especially due to its small size and light weight. With regard to this, a loosening monitoring of bolted joints using optical fiber bending sensor for aircraft lug assembly is proposed in this paper. The lug assembly specimen, which consists of a stainless steel lug, CFRP/Nomex honeycomb sandwich panel, carbon-steel bolt, nut and washer, and the monitoring system, which consists of a single mode fiber with ten optical fiber bending sensor nodes and an Optical Time-domain Reflectometer (OTDR) were used to determine the bolt loosening at every 1 degree interval.

scholarly journals Merancang Sistem Pengukuran Redaman Transmisi Kabel Optik Single Mode Jenis Pigtail

2019 ◽  
Vol 11 (2) ◽  
pp. 56-62
Author(s):  
Aprinal Adila Asril ◽  
Yustini Yustini ◽  
Putri Azizah Herwita
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Protective Layer ◽  
Optical Power ◽  
Single Mode ◽  
Basic Structure ◽  
Transmission Measurement ◽  
Optical Time Domain Reflectometer ◽  
Testing Tools ◽  
Optical Time

Optical fiber is a transmission channel made of glass or plastic that is used to transmit light signals from one place to another. Optical fibers, in general, have a basic structure consisting of a fiber core, a fiber coating (cladding), and a protective layer (coating) consisting of an inner jacket. This research discusses the design of the attenuation of the fiber optic transmission measurement system by connection factor. Optical fiber cable used in this research is pigtail type cable with single-mode cable type. The cable used is 10 meters long, which will be installed in the Optical Termination Box. In the Optical Termination Box there are 6 pigtail cables, which are without connections, with a 6 cm sleeve protection one connection and two connections, also with a 4 cm sleeve protection one connection and two connections, then use a barrel adapter. In this design testing tools use Light source, Optical Power Meter, and Optical Time Domain Reflectometer). The attenuation value after testing on the protection sleeve 6cm; 12,330 dB, then the attenuation on the protection sleeve is 4cm; 12,729 dB. Then attenuation on the barrel adapter; 12,954 dB

Analysis of Optical Backbone Fiber and Trace Report of Break Fiber by Using Optical Time Domain Reflectometer

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Nandhakumar Pandi ◽  
Mohasin Naragund
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Time Domain ◽  
Data Communication ◽  
Single Mode ◽  
Optical Fiber Communication ◽  
Long Distance ◽  
Optical Time Domain Reflectometer ◽  
Optical Time ◽  
Time Domain Reflectometer

AbstractNow a day all the telecommunication industries are using fibers for faster data communication and long distance communication. Fibers use light as the information and it is carried over long distances. Optical fiber has large advantages over a copper and co-axial cable because of its lower attenuation and interference. Optical time domain reflectometer (OTDR) is also one of the important devices using in telecommunication industries to characterize an optical fiber. This article deals with the study of long distance backbone single mode fiber and their features are discussed with the use of an OTDR. The results of this article focused on the losses and breaks of the fiber with the events. The Single mode OTDR is used to find the events, losses and breaks of the backbone fiber between the two locations. This work will give a way to study the nature of optical fibers and understand the practical application of optical fiber communication.

Highly sensitive optical fiber bending sensor based on hollow core fiber and single mode fiber

Optik ◽  
2021 ◽  
Vol 228 ◽  
pp. 166209
Author(s):  
Y.D. Niu ◽  
Q. Chen ◽  
Chunliu Zhao ◽  
D.N. Wang
Keyword(s):  
Optical Fiber ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Hollow Core ◽  
Highly Sensitive ◽  
Core Fiber ◽  
Bending Sensor

scholarly journals Compact omnidirectional multicore fiber-based vector bending sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Josu Amorebieta ◽  
Angel Ortega-Gomez ◽  
Gaizka Durana ◽  
Rubén Fernández ◽  
Enrique Antonio-Lopez ◽  
...  
Keyword(s):  
Single Mode ◽  
High Accuracy ◽  
Single Mode Fiber ◽  
Wavelength Shift ◽  
Short Segment ◽  
Light Power ◽  
Highly Sensitive ◽  
Bending Sensor ◽  
Asymmetric Multicore ◽  
Multicore Fiber

AbstractWe propose and demonstrate a compact and simple vector bending sensor capable of distinguishing any direction and amplitude with high accuracy. The sensor consists of a short segment of asymmetric multicore fiber (MCF) fusion spliced to a standard single mode fiber. The reflection spectrum of such a structure shifts and shrinks in specific manners depending on the direction in which the MCF is bent. By monitoring simultaneously wavelength shift and light power variations, the amplitude and bend direction of the MCF can be unmistakably measured in any orientation, from 0° to 360°. The bending sensor proposed here is highly sensitive even for small bending angles (below 1°).

scholarly journals Microdrilled tapers to enhance optical fiber lasers for sensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. A. Perez-Herrera ◽  
M. Bravo ◽  
P. Roldan-Varona ◽  
D. Leandro ◽  
L. Rodriguez-Cobo ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Lasers ◽  
Signal To Noise Ratio ◽  
Power Level ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Output Power Level ◽  
Linear Cavity

AbstractIn this work, an experimental analysis of the performance of different types of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror is presented. These artificially-controlled backscattering fiber reflectors are used in short linear cavity fiber lasers. In particular, laser emission and sensor application features are analyzed when employing optical tapered fibers, micro-drilled optical fibers and 50 μm-waist or 100 μm-waist micro-drilled tapered fibers (MDTF). Single-wavelength laser with an output power level of about 8.2 dBm and an optical signal-to-noise ratio of 45 dB were measured when employing a 50 μm-waist micro-drilled tapered optical fiber. The achieved temperature sensitivities were similar to those of FBGs; however, the strain sensitivity improved more than one order of magnitude in comparison with FBG sensors, attaining slope sensitivities as good as 18.1 pm/με when using a 50 μm-waist MDTF as distributed reflector.

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