Rayleigh waves in anisotropic crystals rotating about the normal to a symmetry plane

TL;DR

This paper investigates how Rayleigh surface acoustic waves behave in rotating anisotropic crystals, revealing dispersion and deceleration effects, with explicit equations and computed wave speeds for various crystal symmetries and rotation rates.

Contribution

It provides explicit secular equations for Rayleigh waves in rotating monoclinic and orthorhombic crystals, including wave speed calculations across different symmetries and rotation rates.

Findings

Wave is dispersive and slows down with increased rotation

Explicit secular equations derived for monoclinic and orthorhombic crystals

Wave speed computed for multiple crystal types and rotation conditions

Abstract

The propagation of surface acoustic waves in a rotating anisotropic crystal is studied. The crystal is monoclinic and cut along a plane containing the normal to the symmetry plane; this normal is also the axis of rotation. The secular equation is obtained explicitly using the "method of the polarization vector", and it shows that the wave is dispersive and decelerates with increasing rotation rate. The case of orthorhombic symmetry is also treated. The surface wave speed is computed for 12 monoclinic and 8 rhombic crystals, and for a large range of the rotation rate/wave frequency ratio.