Tractable calculation of the Green's tensor for shear wave propagation in an incompressible, transversely isotropic material.

Published

Journal Article

Assessing material properties from observations of shear wave propagation following an acoustic radiation force impulse (ARFI) excitation is difficult in anisotropic materials because of the complex relations among the propagation direction, shear wave polarizations, and material symmetries. In this paper, we describe a method to calculate shear wave signals using Green's tensor methods in an incompressible, transversely isotropic (TI) material characterized by three material parameters. The Green's tensor is written as the sum of an analytic expression for the SH propagation mode, and an integral expression for the SV propagation mode that can be evaluated by interpolation within precomputed integral functions with an efficiency comparable to the evaluation of a closed-form expression. By using parametrized integral functions, the number of required numerical integrations is reduced by a factor of 102-109 depending on the specific problem under consideration. Results are presented for the case of a point source positioned at the origin and a tall Gaussian source similar to an ARFI excitation. For an experimental configuration with a tilted material symmetry axis, results show that shear wave signals exhibit structures that are sufficiently complex to allow measurement of all three material parameters that characterize an incompressible, TI material.

Full Text

Duke Authors

Cited Authors

  • Rouze, NC; Palmeri, ML; Nightingale, KR

Published Date

  • January 13, 2020

Published In

Volume / Issue

  • 65 / 1

Start / End Page

  • 015014 -

PubMed ID

  • 31775132

Pubmed Central ID

  • 31775132

Electronic International Standard Serial Number (EISSN)

  • 1361-6560

International Standard Serial Number (ISSN)

  • 0031-9155

Digital Object Identifier (DOI)

  • 10.1088/1361-6560/ab5c2d

Language

  • eng