MECHANICS AND ACOUSTICS OF METAMATERIALS: MATHEMATICAL MODELING, EXPERIMENTAL RESEARCH, PROSPECTS FOR APPLICATION IN MECHANICAL ENGINEERING
Abstract
An overview of modern publications on acoustic and mechanical metamaterials is presented. The most important characteristic feature of metamaterials is the presence of frequency band gaps in them, i.e. such frequencies at which the waves cannot propagate in the material. This feature has played a major role in the creation of acoustic metamaterials that are successfully used to absorb sound, to damp vibration and shock effects, and to make devices preventing the propagation of waves on a given frequency in certain directions.
Such representatives of mechanical metamaterials as auxetics – materials, at least one of the Poisson's ratios of which is negative, have also proven themselves as advanced materials for practical applications. They are distinguished by high consumer value (low density, high strength, nice insulating properties).
In addition to acoustics and mechanics, in recent years there has been a significant increase in interest in the creation of materials that make it possible to control the flow of light or electromagnetic waves.
It has been also noted that the development of new metamaterials is in high demand for the aerospace and automotive industries, as well as for biomedical applications.
Two basic methods for modeling of metamaterials are considered: the continual-phenomenological description and the structural modeling. Their advantages and disadvantages are listed. The structural modeling method enables one establishing an analytical relationship between the medium macroconstants and its microstructure parameters. As a result, there appears a possibility both to get an idea of the qualitative influence of the microstructure of the medium on its effective elastic moduli and to estimate quantitatively these constants, as well as to find the ranges of values of the microstructure parameters at which the medium possesses unique physical and mechanical properties.
