ABSTRACT
This chapter discusses the effect of the speed of propagation of discontinuities of displacement derivatives on the surface of a non-homogeneous elastic body of arbitrary shape. It illustrates the derivation of homogeneous linear second order equations in a system of elasticity. The boundary conditions on the unloaded surface of the body are replaced by new linear equations with the same values of the coefficients by the highest order derivatives. The methods commonly used for finding, in the simplest case, the speed of propagation of discontinuity waves on the plane surface of an elastic body are applied, no matter whether these waves decay inside the body (Rayleigh waves) or not.
