Transformation Method to Control Shear Horizontal Waves

Abstract

The transformation method is of great interest to control electromagnetic waves and acoustic waves in recent years, but it does not always work to manipulate elastic waves. In this paper, a detailed analysis of controlling the shear horizontal (SH) wave, which is a special form of elastic waves, is presented by employing the transformation method. Two scenarios of setting needed materials are provided, and the equivalence of them is proved theoretically. To reduce the complexity of required material parameters, the case of a changing out-of-plane coordinate is studied. The linear transformation method and the effective medium theory are introduced to control SH waves by using homogeneous and isotropic materials. Moreover, numerical simulations confirm the validity of this approach even in the cases of anisotropic and inhomogeneous background media, which are rarely investigated before. Finally, the multiple transformations method is proposed as a strategy of designing multi-domain and multi-function devices.