CLASSIFICATIONS OF SURFACE-WAVES IN ANISOTROPIC ELASTIC-MATERIALS

Surface waves in an anisotropic elastic material can be classified acc ording to the number of distinct eigenvalues and the number of indepen dent eigenvectors of the 6 x 6 real matrix N(upsilon). There are six g roups under this classification. Surface waves can also be classified according to the number of partial waves in the solution and the form of each partial wave. There are again six groups according to this cla ssification. The classifications encompass both subsonic and supersoni c surface waves. The relationships between the two different classific ations and the existence or non-existence of a surface wave in each gr oup are discussed. We show how one can obtain a set of orthogonal and normalized eigenvectors and generalized eigenvectors for the matrix N( upsilon). The eigenvectors and generalized eigenvectors thar appear in the surface wave solutions belong to a set of orthogonal eigenvectors with few exceptions, although orthonormalization is not required for surface wave construction.