The Polarization of Waves in an Anisotropic Nonlinear-Elastic Medium

In an anisotropic linear-elastic medium, polarization of waves due to anisotropy of the medium is known to occur. In a way similar to phenomena in an anisotropic linear-elastic medium, polarization of waves takes place even in an anisotropic nonlinear-elastic medium. Polarized waves in a nonlinear-elastic medium are also soliton-like or step-shaped waves named simple waves. In an isotropic nonlinear-elastic medium, the simple waves are separated into two categories, non-coupled and coupled simple waves. The former are dilatational waves, while the latter are coupled waves with dilatational (u-component) and distorsional (v- and w-components) properties, where u and {v, w} are longitudinal and transverse components, respectively. In the case of anisotropic nonlinear-elastic medium, two kinds of simple waves mentioned above also appear with some modification due to the presence of anisotropy. The secondary waves produced by anisotropy are exact simple waves instead of only disturbance-type waves. Equations are numerically evaluated by use of an extended finite difference method expanded in a Taylor series. The wave source then has the form of a mountain ridge with a width -4<hx