Distributed Brillouin Scattering Sensor for Discrimination of Wall-Thinning Defects in Steel Pipe under Internal Pressure

Fiber Optics Group, Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada.
Applied Optics (Impact Factor: 1.78). 04/2004; 43(7):1583-8. DOI: 10.1364/AO.43.001583
Source: PubMed


A distributed Brillouin scattering sensor has been employed to identify several inner wall cutouts in an end-capped steel pipe by measuring the axial and hoop strain distributions along the outer surface of the pipe. The locations of structural indentations that constitute 50-60% of the inner pipe wall are found and distinguished by use of their corresponding strain-pressure data. These results are quantified in terms of the fiber orientation, defect size and depth, and behavior relative to those of unperturbed pipe sections.

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Available from: Shahraam Afshar, May 29, 2014
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    • "Apart from a few field installations, such systems have been mostly used in experimental research to evaluate a specific parameter in comparison with more conventional sensors. Several studies have addressed measurement performance when the sensor is attached or embedded in a concrete beam under deflection [13] [14] [15], or to study preembedded defects in steel pipelines [16], composite pipes [17], and well casing [18]. Also, in a study with the same DBS as used in this study, validation of measured bending strain was evaluated in a number of long beams made of concrete, wood, and aluminum with different sensor attachment methods [19]. "
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    • "Bao [6] proposed in-laboratory and in-field measurements concerning beam deflection under bending, investigating the accuracy of the readings. The experiments carried out by Bao [6], Kim et al [8] and more recently by Zou et al [9] clearly showed that the accuracy of the read strains is strongly affected by the spatial resolution of the sensors, which depends on the frequency of the waves; for this reason the local accuracy of readings could actually represent a great problem if strain exhibits strongly localized changes. In particular, this frequently happens for bending beams near the support zones and in the presence of slight modifications of the geometry for technological reasons or when localized damage occurs [10] [11]. "
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