Elastic wave confinement and absorption in a dissipative metamaterial

Abstract

In this paper, we report on the theoretical investigation of the elastic wave confinement and absorption in a dissipative metamaterial, which is constituted of two-dimensional phononic crystals with binary composite material defect composed of aluminum discs hemmed around by damped rubber. Based on an efficient finite element method in combination with a super cell technique, the dispersion relations and the power transmission spectra of the proposed dissipative metamaterialshave been calculated. Numerical results show that the proposed dissipative metamaterials can yield complete band gap as well as defect states. Elastic waves of the specific frequency of the defect models in the range of gap frequencies have been confined and dissipated simultaneously in the point defect or along the line defects. In contrast to the traditional damper for vibration energy dissipation, the proposed dissipative metamaterials can be equivalent to elastic wave energy attractor and possess significant higher energy dissipation rate for ambient distributed vibration. These elastic wave confinement and dissipation properties of the proposed dissipative metamaterials can potentially be utilized to generate vibration absorbers as well as optimization design of damped structure.