We study the coupled macroscopic and lattice wave propagation in anisotropic crystals seen as continua with affine microstructure (or micromorphic). In the general anisotropic case we obtain qualitative informations on frequencies and dispersion relations. We also show that in any anisotropic crystal we have three acoustic and nine optic waves. These results are then specialized to the crystals of the tetragonal point group for various propagation directions: exact representation for the acoustic and optic frequencies and for the coupled vibrations modes are obtained for propagation directions along the tetragonal c-axis as well as for some special directions orthogonal to it.
Coupled bulk and lattice waves in crystals seen as micromorphic anisotropic continua, with an application to crystals of the tetragonal group / Davi', Fabrizio. - In: ADVANCES IN APPLIED MECHANICS. - ISSN 0065-2156. - STAMPA. - (2023), pp. 1-88. [10.1016/bs.aams.2023.09.002]