### ASA 127th Meeting M.I.T. 1994 June 6-10

## 4pPA13. Transformation of SH wave into a Stoneley wave under weak
distortion of a crystal lattice of the material of an elastic isotropic space.

**Yuriy A. Rossikhin
**

**
Marina V. Shitikova
**

**
**
*Dept. of Theor. Mech., Voronezh State Acad. of Construction and
Architecture, ul. Kirova 3-75, Voronezh 394018, Russia
*

*
*
The problem on transformation of a volume SH wave propagating along an
isotropic elastic space into a Stoneley wave in the consequence of the
conversion of this space into a three-layered medium by small variations in
material elastic moduli in a portion of the space is considered. The
three-layered medium of two types has been investigated: A weakly anisotropic
layer of cubic symmetry between two isotropic half-spaces and an isotropic
layer between two slightly anisotropic half-spaces of cubic symmetry. In doing
so, the elastic moduli of an isotropic material and isotropic parts of the
moduli of a weakly anisotropic material are the same. Small anisotropic
additions to the isotropic elastic moduli are entered by various means, so that
velocities of SH waves in the slightly anisotropic materials with cubic
symmetry obtained in such a way may be smaller, bigger, or equal to the
velocity of SH waves in the corresponding isotropic material. It is shown that
in those cases when the Stoneley wave exists, it refers to a weakly
inhomogeneous quasitransverse wave of SH type, because among three displacement
components weakly decaying with depth, the transverse one, which is parallel to
the interface of three mediums, predominates.