ASA 127th Meeting M.I.T. 1994 June 6-10

4pSAb4. Order and disorder in ribbed membranes with fluid loading.

Mark Spivack

Dept. of Appl. Math. & Theor. Phys., Univ. of Cambridge, Cambridge CB3 9EW, UK

Paul E. Barbone

Boston Univ., Boston, MA 02215

The response to harmonic forcing both of regularly and of irregularly ribbed fluid-loaded membranes has been studied under the assumption of subsonic wave coupling. The solution for any given rib configuration is obtained exactly in terms of 2x2 transfer matrices. In the irregular case it is well known that localization occurs at all driving frequencies; nevertheless there are distinct regimes of smooth and fluctuating decay. These are shown to be closely related to the stop- and passbands found in regularly supported membranes, and this is explained in terms of the characteristics of the transfer matrices. This approach can be generalized to any problem in which the long-range behavior of the Green's function is the same as for the case of subsonic wave coupling. [Work supported by Smith Institute Research Fellowship and ONR.]