On the basis of a model for a so-called plastically incompressible medium with dissipation, the nature of the vibrations in an unbounded medium with dislocations was considered. The inclusion of the dissipation of weakly-damped low-frequency vibrations of volume contraction and high-frequency longitudinal sound vibrations was shown to cause a considerable change in the structure of the normal vibrations. For a given dissipation, weakly-damped low-frequency vibrations of volume contraction and high-frequency longitudinal sound vibrations were described by one branch of the dispersion relationship. The structure of the vibrations changed, from so-called liquid-like, to longitudinal sound vibrations in the neighborhood of the boundary frequency of optical vibrations. A model which included energy dissipation did not describe the so-called Cosser liquid.

Configuration of Normal Vibrations in an Unbounded Medium Containing Dislocations with Allowance for Energy Dissipation. N.V.Chertova: Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, 1995, 38[3], 40-4 (Russian Physics Journal, 1995, 38[3], 254-7)