Using high-frequency vibrations and non-linear inclusions to create metamaterials with adjustable effective properties

We investigate how high-frequency (HF) excitation combined with strongly non-linear elasticity may influence the effective properties for low-frequency wave propagation. The HF effects are demonstrated for linear spring-mass chains with embedded non-linear parts. The investigated mechanical systems can be viewed as a one-dimensional model of materials with non-linear inclusions. The presented analytical and numerical results show that effective material properties can be altered by establishing HF standing waves in the non-linear regions of the chain. In addition, it is demonstrated how true static displacements and forces can be created by using HF excitation with structures having asymmetric displacement-force characteristics.