Acoustic metamaterials with controllable transmission: from complete sound attenuation to a transparent state.
Tutor / director / evaluatorVan Wunnik, Lucas Philippe
Document typeMaster thesis
Rights accessRestricted access - author's decision
This project deals with the design and analysis of sound scattering in acoustic metamaterials with the aim to realize a controllable transmission response. First, a so-called stealth acoustic metamaterial is studied. This is a metamaterial with non-periodic rigid scatterers that suppress acoustic scattering at predefined frequencies. Although the literature reports a single stealth one-dimensional configuration, here we show that this configuration is not unique (for the specified geometric parameters) and that the sound transparent behaviour can be achieved by simply relocating the scatterers. To optimize their positions, we have developed four algorithms generating feasible configurations, which are based on a random choice and three optimization procedures. The algorithms are not restricted to the stealth behaviour, but are shown to perform well to achieve any desired transmission value. This opens bright perspectives to the development of non-periodic acoustic metamaterials with controllable transmission. In particular, we show how a plane wave front can be changed to a half-sin function form. The acoustic characteristics of the proposed metamaterials have been studied analytically, and the obtained results are verified by finite-element simulations.
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