Bandgap Broadening in a Membrane Acoustic Metamaterial with Multiple Resonaters and Membrane Layers
* Presenting author
Locally resonant acoustic metametrials (LRAM) are known as an innovative solution to acoustic insulation, which possess a high efficiency in sound attenuation besides compactness and low weight. However, they present their outstanding functionality at a narrow frequency range, known as bandgap. This tightly limited operation range of LRAMs is considered as their most important disadvantage. In this study, the performance of a membrane type acoustic metamaterial in presence of a concentrated force is examined numerically by calculating its velocity level using Finite Element Method (FEM). Also, its bandgap is attempted to be extended by multiplying local resonances within the LRAM by using multiple resonators, multiple membrane layers and combination of these two methods.