Characterization of SH and SV Wave Modes in a Nonlinear Elastic Solid with Uniaxial Stretch Using 3D-Rotational SWEI

We present a 3D-RSWEI characterization of a polyvinyl alcohol phantom with applied uniaxial stretch at multiple transducer tilt angles (0<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup>, 15<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup>, 30<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup>, and 45<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup>), building on previous work [1]. We have observed shear horizontal (SH) and complex shear vertical (SV) wave mode propagation at large stretch ratios and at 15<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup> and 30<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup> of tilt. We have compared analytically calculated shear wave speeds assuming an Isihara material model to experimentally measured speeds in the PVA phantom to re-derive estimates of uniaxial stretch ratios. This analysis indicates the potential for 3D-RSWEI in higher order nonlinear elasticity characterization methods.