A Numerical Study on the Potential of Acoustic Metamaterials

In the present contribution we are going to investigate a special class of acoustic metamaterials, i.e. synthetic foams with spherical inclusions. This study is motivated by the need for an improved acoustical behavior of engines and vehicles which is one important criterion for the automotive industry. In this context, innovative materials offering a high damping efficiency over a wide frequency range are becoming more and more important. Since there is an innumerable selection of different absorbing materials with an equally large range of properties numerical studies are inevitable for their assessment. In the paper at hand, we look at a special class of such materials in which the influence of the inclusions on the acoustical behavior is examined in detail. To this end, we vary the size, mass density, number and position of spherical inclusions. Here, the main goal is to improve the damping properties in comparison to conventional materials which can be bought off the shelf. In that regard, the lower frequency range is of special interest to us. The results show that a random distribution of the inclusions should be favored while for the other parameters values that are centered within the investigated interval are recommended.