Guided wave techniques have great potential for the structural
health monitoring of plate-like components. Previous research has
demonstrated the effectiveness of combining laser-ultrasonic
techniques with time-frequency representations to experimentally
develop the dispersion relationship of a plate; the high fidelity,
broad bandwidth and point-like nature of laser ultrasonics are
critical for the success of these results. Unfortunately, laser
ultrasonic techniques are time and cost intensive, and are
impractical for many in-service applications. Therefore this
research develops a complementary digital signal processing
methodology that uses mounted piezoelectric elements instead of
optical devices. This study first characterizes the spatial and
temporal effects of oil coupled and glued piezoelectric sources,
and then develops a procedure to interpret and model the
distortion caused by their limited bandwidth and finite size.
Furthermore, it outlines any inherent difficulties for time and
frequency domain considerations. The deconvolution theory for
source function extraction in the time - and frequency domain
under the presence of noise is provided and applied to measured
data. These considerations give the background for further studies
to develop a dispersion relationship of a plate with the fidelity
and bandwidth similar to results possible with laser ultrasonics,
but made using mounted piezoelectric sources.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/4792 |
| Date | 19 August 2004 |
| Creators | Kreuzinger, Tobias |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 7495086 bytes, application/pdf |
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