### ASA 125th Meeting Ottawa 1993 May

## 4pUW10. Solution of wave scatter problems in poroelastic media using exact
analytical and boundary integral equation methods.

**Chris Zimmerman
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*Appl. Res. Lab.
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**M. Stern
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*Univ. of Texas at Austin, Austin, TX 78712
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Methods are developed for obtaining solutions to the harmonic form of the
equations governing wave propagation and wave scatter in a poroelastic medium.
An analytical solution in the form of an infinite series is obtained for the
problem of scatter of an incident plane compression wave by a sphere. The
incident wave may be composed of any linear combination of Biot ``fast'' and
``slow'' waves, and the sphere may be fixed and rigid, may be composed of
elastic solid, or it may be a fluid-filled cavity. A desingularized set of
boundary integral equations is developed for the harmonic problem, and these
are incorporated into a three-dimensional boundary element computer program.
Results obtained from this boundary element program are compared to results
obtained using the series solution discussed above. The forbidden frequency
problem is shown to be inherently absent from the poroelastic problem.