Time Domain Construction of Acoustic Scattering by Elastic Targets Through Finite Element Analysis

A. Gunderson [1], B. Simon [1], A. Bonomo [1], M. Isakson [1],
[1] Applied Research Laboratories, University of Texas - Austin, Austin, TX, USA
Published in 2017

Finite element models for acoustic scattering from three dimensional underwater elastic objects, calculated in the frequency domain, are transformed to the time domain through Fourier synthesis using COMSOL Multiphysics®. The time domain mirrors the way in which experimental scattering data from real targets is acquired. Fluid elements are modeled using built-in physics in COMSOL’s acoustics module, while elastic target elements are modeled with user-defined weak-form PDE interfaces. The problem is evaluated using a 2D axisymmetric geometry in COMSOL, and is extended to three dimensions through an axial wavenumber decomposition technique. Results show good agreement with established analytical solutions in both frequency and time domains.