Sound of a chessboard: homogenization of wave motion in periodic solids

This work [59] illustrates the pursuit of a formal two-scale homogenization approach to extract the mean wave motion in bi-periodic solids, including the effect of incipient dispersion. We show that such low-frequency expansion leads to a family of fourth-order PDEs (resembling the phenomenological models of gradient elasticity) whose coefficients derive explicitly from the microstructure.