The problem of the propagation of nonlinear waves in complex solids, namely bodies with different internal microstructures, is analyzed. In the first part, we make use of a general model of microstructured solids as introduced by Engelbrechet and Pastrone (Acc Sc Torino Mem Sc Fis 2011; 35: 23–36) and study two particular relevant models: one-dimensional solid with hierarchical microstructure and with concurrent microstructures. As expected, the hierarchical microstructure leads, with a particular but meaningful choice of the strain energy function, to a sixth-order partial differential equation (PDE) with a characteristic hierarchical structure. Hence, the case of two concurrent microstructures, as introduced by Berezovski, Engelbrecht and Berezovski (Acta Mech 2011; 220(1–4): 349–363), is studied and again for suitable explicit forms of the energy function we can obtain a fourth-order PDE and actually prove the possibility of propagation of solitary and cnoidal waves.
