CaltechAUTHORS
Published May 2018 | Version Published + Supplemental Material
Journal Article Open

Hybridization of Guided Surface Acoustic Modes in Unconsolidated Granular Media by a Resonant Metasurface

Creators

  • 1. ROR icon University of Bologna
  • 2. ROR icon California Institute of Technology
  • 3. ROR icon ETH Zurich
  • 4. ROR icon University of Illinois Urbana-Champaign

Abstract

We investigate the interaction of guided surface acoustic modes (GSAMs) in unconsolidated granular media with a metasurface, consisting of an array of vertical oscillators. We experimentally observe the hybridization of the lowest-order GSAM at the metasurface resonance, and note the absence of mode delocalization found in homogeneous media. Our numerical studies reveal how the stiffness gradient induced by gravity in granular media causes a down-conversion of all the higher-order GSAMs, which preserves the acoustic energy confinement. We anticipate these findings to have implications in the design of seismic-wave protection devices in stratified soils.

Additional Information

© 2018 American Physical Society. Received 3 November 2017; revised manuscript received 1 April 2018; published 17 May 2018. We acknowledge Viktor Thöni for the help in the construction of the experimental setup and for the initial measurements of the GSAMs velocities. We thank Virginia von Streng for the help in designing the 3D printed resonators and Isotta Carpi for the help in the preliminary numerical models. This work was partially supported by the Swiss National Science Foundation (Grant No. 164375) to C. D., by the ETH Research Grant (49 17-1) to R. Z., and an ETH Postdoctoral Fellowship to K. H. M.

Attached Files

Published - PhysRevApplied.9.054026.pdf

Supplemental Material - Supplementary_final.pdf

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PhysRevApplied.9.054026.pdf

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Additional details

Identifiers

Eprint ID
86438
Resolver ID
CaltechAUTHORS:20180517-100308712

Funding

Swiss National Science Foundation (SNSF)
164375
ETH Zurich
49 17-1
ETH Postdoctoral Fellowship

Dates

Created
2018-05-18
Created from EPrint's datestamp field
Updated
2021-11-15
Created from EPrint's last_modified field