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

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.