Wave propagation in unbounded media is a topic widely studied in different science
and engineering fields. Global and local absorbing boundary conditions combined with
the finite element method or the finite difference method are the usual numerical
treatments. In this dissertation, an alternative is investigated based on the dynamic
stiffness and the exponential window method in the space-wave number domain.
Applying the exponential window in the space-wave number domain is equivalent to
introducing fictitious damping into the system. The Discrete Fourier Transform employed
in the dynamic stiffness can be properly performed in a damped system. An open
boundary in space is thus created. Since the equation is solved by the finite difference
formula in the time domain, this approach is in the time-wave number domain, which
provides a complement for the original dynamic stiffness method, which is in the
frequency-wave number domain.
The approach is tested through different elasto-dynamic models that cover one-,
two- and three-dimensional problems. The results from the proposed approach are
compared with those from either analytical solutions or the finite element method. The
comparison demonstrates the effectiveness of the approach. The incident waves can be
efficiently absorbed regardless of incident angles and frequency contents. The approach
proposed in this dissertation can be widely applied to the dynamics of railways, dams,
tunnels, building and machine foundations, layered soil and composite materials.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2693 |
| Date | 15 May 2009 |
| Creators | Liu, Li |
| Contributors | Roesset, Jose |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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