Acoustic Transparency of Non-homogeneous Plates (with repeating inclusions) using Periodic Structures Methodology

A. J. Kalinowski
Naval Undersea Warfare Center/Div. Npt. Newport, RI, USA

The paper addresses a class of problems for determining the acoustic interaction of time-harmonic plane waves impinging upon submerged elastic plates (fluid backed or void backed), that are infinite in extent.

The plates can have repeated equally spaced inclusions (voids, solids, ribs etc.), and also can be constructed from orthotropic and/or isotropic layers that can have a frequency dependent loss factor for the modulus data.

Since the plates are infinite in extent, the issue of dealing with the infinite domain of fluid must be dealt with and is treated through the application of PML (Perfectly Matched Layers) boundary conditions, for absorbing the reflected acoustic waves and transmitted acoustic waves when the plates are fluid backed.