“…This situation is similar to one with plane bulk shear acoustic waves [29,37,38]. The lowest order nonlinearity which is currently under the consideration for flexural motion in homogeneous materials is classical cubic elastic nonlinearity (of odd-type in its symmetry and cubic in its dependence on the wave amplitude) [39][40][41]. The theories of flexural waves, which include the classical elastic nonlinearities only, could be not relevant for the flexural waves propagation in micro-inhomogeneous plates where other types of nonlinearities, i.e., nonclassical nonlinearities, could dominate [28,31].…”