RAYLEIGH-LAMB WAVE PROPAGATION IN ANISTOTROPIC MEDIA.

The stiffness matrix relating stress to strain in the generalized Hookes Law can, for anisotropic materials, be written in terms of the isotropic matrix plus a set of perturbation terms. This matrix and the Rayleigh-Lamb displacement field are used to determine special forms of the equilibrium equations for anisotropic Rayleigh-Lamb waves. The forms of anisotropy were restricted to the hexagonal, orthorhombic, cubic, and tetragonal crystal classes, and a frequency equation which is an anisotropic analog to the equation published by Lamb in 1917 was developed for these materials. Perturbation effects on the frequency equations were then examined. Author