This research focuses on the application of guided waves techniques
to nondestructively characterize the structural integrity of bonded
engineering components. Computational methods are used to examine
the properties of multi-layered, adhesive bonded plates. This study
quantifies the effect of the adhesive bond parameters (Young's
modulus, Poisson's ration and bond thickness) on the dispersion
curves. A commercial finite element (FE) code (ABAQUS/Explicit) is
used for the numerical model while the global matrix method and the
waveguide FE method are used to benchmark the resulting dispersion
relationships in the form of a frequency-wavenumber or
slowness-frequency relation. The postprocessing of FE data includes
the two-dimensional Fourier transform (2D-FFT) and the short-time
Fourier transform (STFT). Note that the 2D-FFT and STFT operate on
multiple or just one transient output signals of the FE results
respectively, while the waveguide FE method uses mass-, damping- and
stiffness-matrices to generate the dispersion relations. In the
dispersion relations, a set of bond parameter sensitive and
FE-visible points is selected. The frequency locations of these
points represent the solution criteria for the inversion procedure
based on the global matrix method. The capabilities of the inversion
process depend on the number of transient output signals from an FE
simulation for the forward problem.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/14121 |
| Date | 25 August 2006 |
| Creators | Koreck, Juergen |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 1321680 bytes, application/pdf |
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