Reflected Flexural Wave Manipulation Based On Ultra-Thin Elastic Metasurface

In this paper, we propose a new type of ultra-thin elastic metasurface (UEM) consisting of mass-spring resonant stubs to manipulate flexural wave in a deep subwavelength (the metasurface thickness is 1/16 of the wavelength). The designed resonant stubs composed of lead and rubber blocks are presented to induce strong locally resonances. The full phase control for reflected flexural wave could be obtained by choosing proper natural frequencies of the resonant stubs. Then, the UEM is theoretically designed to achieve the abnormal reflection of the incident flexural wave based on the generalized Snell's law (GSL). The results obtained by finite element simulation validate the effectiveness of abnormal reflecting functionality of UEM. The present study demonstrates that the designed elastic metasurface can pave the way for flexural wave manipulation, and it has the great potential in the engineering fields of vibration control, nondestructive evaluation and energy harvesting.