Effect of embedded resonators in sound insulation panels - A numerical study

Acoustic metamaterials are a current topic of research for many applications. One such application is related to the definition of new sound insulation solutions which avoid well know dynamic phenomena such as the coincidence effect. The present paper studies the behaviour of a specific metamaterial-based solution in which specific elements are embedded in the sound insulation panel itself, forming a structure with complex dynamic behaviour. The main goal is to perform an initial study on the possibility of developing a simple strategy to incorporate resonant structures in wall panels, with the aim of reducing the effect of the critical frequency (coincidence effect) on the sound insulation of such panels. Both 1D and 3D periodic Finite Element models are used in this study, identifying not only the dispersion curves associated with the different modes of the structures but also trying to predict the global sound reduction provided by this complex element. A parametric study is presented to illustrate the concept and to evidence the expected benefits in terms of sound reduction.