Finite element modelling of the sound trasmission properties of a symmetric metaabsorber composed by sided branch helmholtz resonators

In the present study, the authors develop a subwavelength open acoustic metamaterial, composed by the axial coupling of sided branches Helmholtz resonators. A finite element model was developed and the results demonstrate the proposed absorber system works on a subwavelength regime, allowing low-frequency broadband absorption (approx. 500 Hz to 800 Hz). Finally, an experimental campaign was realized at the Department of Engineering of the University of Ferrara, and the simulated results showed good agreement when compared with two standardized methodologies, the ISO 10534-2 and the ASTM E2611-09.