Source location in thin plates using crosscorrelation.
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Author
Ziola, Steven Michael
Date
1991-12Advisor
Gorman, Michael R.
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Show full item recordAbstract
Alternative methods to first threshold crossing techniques for acoustic emission
(AE) source location in dispersive media are presented. The accuracy of source
location in dispersive media can be improved by locating frequency components in
the transducer outputs to determine the difference in arrival times. Two methods
were developed in this study for the arrival time determination. The first involved
crosscorrelating the transducer outputs with a cosine wave modulated by a Gaussian
pulse to locate a single frequency in the outputs. The second method narrowband
filtered the transducer outputs and then crosscorrelated the filtered signals to
determine the difference in arrival times. The techniques were experimentally
verified by performing lead breaks on the surface of aluminum and graphite/epoxy plates. The results indicate that accurate source location can be attained in
dispersive media by taking the wave propagation into account.
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