Lamb waves in elastic layers with rhombic symmetry

Dispersion equations are derived for vertically polarized elastic waves propagating in a rhombically anisotropic layer. It is shown that such a dispersion equation yields dispersion equations for symmetric and antisymmetric modes. In the short- and long-wavelength limits, the existence conditions for Rayleigh waves are determined along with the limiting velocities for thin layers. It is found that, for isotropic layers, the values of these velocities coincide with the known values.