A note on elastic surface waves

Abstract

The structure of harmonically time-dependent free surface waves on a homogeneous, isotropic elastic half-space can be described by proceeding from the following assumptions: (1) the plane boundary is free of surface traction; (2) the Laimé potentials, and consequently all physical quantities, decay exponentially with distance away from the boundary. In the absence of further a priori assumptions, the resulting surface waves need be neither plane nor axially symmetric, and thus the derivation sketched here constitutes a generalization of the ones usually given in the textbook literature [e.g., Love, 1944; Ewing et al., 1957]. With reference to Cartesian coordinates χ_1, χ_2, χ_3, the half-space under consideration occupies the region x_3≥0. The displacement vector u of a typical point has Cartesian components u_j, and the associated components of stress are denoted by τ_(jk). The summation convention is used, Latin and Greek subscripts have the respective ranges 1, 2, 3 and 1, 2, and a subscript preceded by a comma indicates differentiation with respect to the corresponding coordinate.