Wave motion in finite and infinite media using the Thin-Layer Method

The Thin-Layer Method (TLM) is a semi-analytical technique that is efficient for wave propagation problems involving partially heterogeneous media. While the method has been used widely for horizontally stratified media, e.g. dynamic response of foundations over layered soils, there remain many unexplored aspects. These include a thorough evaluation of the TLM's accuracy and range of applicability as well as its extension to semi-infinite and infinite media. Based on these considerations, we have three main goals to pursue in this study. The first one is to explore and improve the accuracy and convergence of the TLM associated with finite media. The second one is to extend the applicability of the TLM to model and analyze semi-infinite and infinite multilayered media. The third one is to develop two novel TLM's that are useful in analyzing wave motions in cylindrically or spherically laminated solids and shells. We proceed our study by separating it into the following three parts. In the first part, we begin by characterizing numerical dispersion phenomena in the TLM by means of general solutions and frequency spectra for discrete homogeneous full-spaces, which are obtained in closed-form with the aid of a finite difference scheme. Then, we determine the optimal combination of the consistent and lumped mass matrices by introducing tuning factors into the discrete system of equations. As a result, we improve the accuracy of not only the eigenvalues associated with free-vibration problems, but also the modal responses to external dynamic loads.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Park, Joonsang, 1969-

Advisor dc:contributor.advisor

• Eduardo Kausel.

• Civil and Environmental Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/43616

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/43616