The basic concepts for modelling wave propagation in solids with microstructure are described. It is shown that the Green method, based on postulating the potential energy function, has certain advantages compared with the widely used Cauchy method, which postulates directly the stress-strain relations. Simple examples demonstrate how the Green method together with internal variables permits to determine the microstress and the interactive force between the constituents of solids. The structure of governing equations and possible physical effects captured by such modelling are described. The microstress and interactive force lead to the dispersion of waves at the macrolevel.
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