Long-range order Bragg scattering and its effect on the dynamic response of a Penrose-like phononic crystal plate

TL;DR

This study investigates how aperiodic scatterer arrangements in a thin elastic plate influence wave scattering, revealing frequency-dependent behaviors including isotropic dispersion at low frequencies and localization at higher frequencies, supported by experiments and simulations.

Contribution

It introduces the analysis of scattering and localization in aperiodic phononic crystal plates, highlighting effects not observed in periodic structures.

Findings

Strong scattering points linked to non-trivial dispersion

Frequency regimes with isotropic dispersion and localization

Validation through experiments and numerical simulations

Abstract

In this article, we present scattering and localization phenomena in a thin elastic plate comprising an aperiodic arrangement of scatterers. By analysing the form factor of the scattering cluster, we sample the reciprocal space which shows strong scattering points associated with non trivial dispersion. Wide frequency regimes with very different dynamic responses are identified: isotropic wave dispersion at low frequency, and an attenuating regime with strong localization effects at higher frequencies. Illustrative comparisons are drawn with a periodic counterpart having the same density of scatterers. The novel findings are corroborated by analytical estimates, numerical finite-element simulations and vibrometric experiments. The results are relevant for the research community interested in extending phononic crystal phenomena to lower frequencies.