Lamb waves as thickness vibrations superimposed on a membrane carrier wave

Classical Lamb waves in an homogeneous, isotropic linearly elastic plate are reconsidered. The displacement components are obtained in terms of thickness motions superimposed on a membrane carrier wave which defines the propagation along the plate. The carrier wave can be any solution of the reduced wave equation for a membrane. The analysis of the thickness motions results in the usual Rayleigh-Lamb frequency equation. A number of special cases for the carrier wave are considered. (C) 1998 Acoustical Society of America.