Viscoelastic surface waves of an assigned wavelength

Propagation of surface waves of an assigned wavelength on a viscoelastic half-space is considered. It is shown that there exists a unique viscoelastic surface wave of an assigned wavelength, which satisfies the adopted criteria for behaviour at infinity. This wave is interpreted as a superposition of two dispersive inhomogeneous plane waves. The superposed waves have different directions of propagation and different phase velocities. Their directions of propagation are not parallel to the stress-free surface. The plane of constant amplitude that corresponds to each of the superposed waves is parallel to the stress-free surface and moves to it with constant velocity which is different for each of the superposed waves. The numerical computations refer to some typical values of the material constants and to some real materials.