Uncertain acoustic meta-atoms
* Presenting author
Acoustic metamaterials (AMMs) consist of periodic arrangements of single meta-atoms (e.g. Brillouin zones). The AMMs can manipulate the acoustic wavepropagation in ways that are not found in nature or conventional materials.Furthermore, AMMs can have unnatural material properties such as a negativeeffective mass or band gaps. One type of meta-atom is based on the principle ofa Helmholtz resonator that is embedded in a fluid matrix. A periodic arrange-ment of such meta-atoms in the two dimensional space combines the effects ofa resonator and those of phononic crystals. The effectiveness of that kind ofAMM depends on the eigenfrequencies of the resonators and the relative posi-tion of one meta-atom to one another. Since the production of AMMs is linkedto manufacturing tolerances the perfect periodicity is not fulfilled and can affectthe properties of the AMM.This work deals with the uncertainties of the meta-atoms concerning the geometry of the embedded resonator. The uncertain geometry parameters areapproximated by spectral expansions. Further, the transfer function and the insertion loss with respectto the uncertain parameters are analyzed. Finally, the results of the spectralapproach are compared to those of the Monte Carlo method.