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Fiber optic methods for nondestructive testing

This thesis demonstrates the use of fiber optic methods for nondestructive testing of composite materials and aluminum specimens using the acousto-ultrasound approach. A noncontact method using a hybrid interferometer is devised for measuring absolute surface acoustic wave (SAW) amplitudes. The J1..J4 spectrum analysis technique is used for calibrating the piezoelectric transducer cylinder (PZT) and JO/J2 spectrum analysis technique is used for demodulating the SAW signal from the interferometer. An extrinsic Fabry-Perot interferometric (EFPI) sensor is utilized for sensing acoustic emission, measuring speed and attenuation in aluminum and composite specimens. A broadband preamplifier is designed for amplifying signals from the EFPI sensor. Theoretical and practical minimum detectable air gap change of an EFPI sensor are calculated for the system. The directional sensitivity of the EFPI sensor to SAW is studied. / Master of Science

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/40577
Date10 January 2009
CreatorsRudraraju, Sridhar
ContributorsElectrical Engineering
PublisherVirginia Tech
Source SetsVirginia Tech Theses and Dissertation
LanguageEnglish
Detected LanguageEnglish
TypeThesis, Text
Formatvi, 61 leaves, BTD, application/pdf, application/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/
RelationOCLC# 31467654, LD5655.V855_1994.R837.pdf

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