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An Application of Elastodynamic Reciprocity to Reflection by an Obstacle in a Waveguide

Published online by Cambridge University Press:  05 May 2011

J.D. Achenbach*
Affiliation:
Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL 60208, U.S.A.
*
*professor
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Abstract

The reciprocal identity which connects two elastodynamic states, denoted by A and B, is used in this paper to obtain two results for an elastic layer. The first is an orthogonality condition for wave modes. For that case the states A and B are wave modes propagating in the same direction. The second result concerns reflection and transmission of wave motion by an obstacle in the layer. Now state A is defined by a superposition of incident wave modes and its reflection and transmission by the obstacle. Expressions for the reflection and transmission coefficients are obtained by selecting counter propagating wave modes for state B. It is also shown that the reflection by an obstacle in a layer can be extended to obtain the reflection and transmission coefficients for a planar array of obstacles in an unbounded elastic solid. For clarity all results are presented for horizontally polarized transverse wave motion.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2000

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References

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