Files and links (1)
PDFOpen Access (License Unspecified), Open Access
Dissertation
Some theoretical and experimental aspects of the generation of guided elastic waves using finite sources
Doctor of Philosophy (Ph.D.), Drexel University
1992
DOI:
https://doi.org/10.17918/00000659
Abstract
In this thesis, the problem of the excitation of linearly elastic waveguides by applied surface tractions is examined. Attention is focussed on flat layer waveguides of arbitrary anisotropy, and isotropic hollow circular cylinder waveguides. In the first two sections, the applied tractions are assumed to be time harmonic, and the Normal Mode Expansion Technique is used to determine the field inside the waveguide due to the loading. In this technique, the fields in the loaded waveguide are expanded in terms of the normal modes permissible in the free waveguide multiplied by unknown expansion coefficients. Use of the complex reciprocity relation and an orthogonality relationship between free waveguide modes enables the determination of the expansion amplitudes, hence the fields in the loaded waveguide. Expressions are given for the amplitude with which any propagating mode of the structure is generated due to the applied surface tractions. The principle of linear superposition is then employed to determine the field generated by a transducer producing finite time duration loading, by superimposing time harmonic solutions via an integration over the dispersion curves of the structure. Finally, several experiments are performed to verify the analysis.
Metrics
28 File views/ downloads
21 Record Views
Details
- Title
- Some theoretical and experimental aspects of the generation of guided elastic waves using finite sources
- Creators
- John Joseph Ditri
- Contributors
- Joseph Lawrence Rose (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- ix, 130 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- College of Engineering (1970-2026); Mechanical Engineering (and Mechanics) [Historical]; Drexel University
- Other Identifier
- 991014970195504721