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

Appl. Res. Lab.

M. Stern

Univ. of Texas at Austin, Austin, TX 78712

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.