Flexural wave absorption by lossy gradient elastic metasurface

Liyun Cao (1, 2) , Zhichun Yang (1) , Yanlong Xu (1) , Shi-Wang Fan (2) , Yifan Zhu (2) , Zhaolin Chen (1) , Yong Li (3) , B. Assouar (2)

1 NPU - Northwestern Polytechnical University [Xi'an]
2 IJL - Institut Jean Lamour
3 Tongji University

In this research, we systematically study the flexural waves diffraction. Based on the diffraction mechanism, we propose the concept of subwavelength lossy gradient elastic metasurface for flexural waves absorption. We theoretically reveal that the highefficiency absorption behavior stems from maximum multireflection-enhanced absorption of 0 th order diffraction, and experimentally show that robust flexural wave quasi-omnidirectional absorption in the frequency range extending approximately from 340 Hz to 1000 Hz (larger than 1.5 octaves). In addition, we propose a general approach which involves new physics of adjusting the arrangement sequence of subunits to suppress the 1 st diffraction mode, to further reduce the sub-wavelength thickness of the metasurface while maintaining its high-efficiency absorption. Our designs could provide new routes to broadband vibration suppression and cancellation in lowfrequency by lossy elastic metamaterials and metasurfaces.

Domaines: Mécanique [physics]

Liyun Cao, Zhichun Yang, Yanlong Xu, Shi-Wang Fan, Yifan Zhu, et al.. Flexural wave absorption by lossy gradient elastic metasurface. Journal of the Mechanics and Physics of Solids, 2020, 143, pp.104052. ⟨10.1016/j.jmps.2020.104052⟩. ⟨hal-03043149⟩