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

Abstract

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 of 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 (e.g. E= E'(1+ietaE), and nu=nu'(1+ieta(nu)), where eta(E) and eta(nu) are the corresponding loss factors for Young's modulus and Poisson's ratio for example. 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. The physical quantities of interest are typically the reflected acoustic waves and transmitted acoustic waves, however detailed information of how the elastic stress waves propagate through and around the inclusions are often of interest as well.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2007
Accession Number
ADA592630

Entities

People

  • Anthony J. Kalinowski

Organizations

  • Naval Undersea Warfare Center

Tags

Communities of Interest

  • Air Platforms
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Waves
  • Acoustics
  • Boundaries
  • Computer Programs
  • Doppler Effect
  • Free Field
  • Frequency
  • Inclusions
  • Materials
  • Modulus Of Elasticity
  • Plane Waves
  • Radiation
  • Scattering
  • Shear Modulus
  • Stiffness
  • Stress Waves
  • Transparencies

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Structural Dynamics.

Technology Areas

  • Space