Characteristic Wave Surfaces in Anisotropic Laminated Plates

A numerical method is used to determine the dispersion relation (an eigenvalue equation) of plane wave propagation in an anisotropic laminated plate. A phase velocity surface, phase slowness surface, phase wave surface, group velocity surface, group slowness surface, and group wave surface are defined and their formulae are deduced from the Rayleigh quotient and the orthogonality condition of the eigenvectors of the eigenvalue equation. The six characteristic surfaces can be used to illustrate the characteristics of plane waves and waves generated from a point source in an anisotropic laminated plate. As numerical examples, the characteristic surfaces are computed for graphite/epoxy angle ply laminated plates and for a hybrid one. The results for the graphite/epoxy laminated plates are compared with those obtained by Moon’s approximate theory.