Sound insulation properties of plate-type acoustic metamaterial structures with different types of resonators

Low frequency noise control is difficult due to the large wavelength. Acoustic metamaterials (AMs) bring a new sight for low frequency noise control because they can control low frequency wave with subwavelength structures. Since plate type structures are widely used in engineering, the plate type AM structures with different types of resonators are studied by both experiments and numeric simulations. The measured sound transmission loss (STL) curves of the samples show that there are several peak points appearing in the low frequency range. It is found from the numerical simulations that sound wave cannot transmit the plate at these points. The certain locally resonant modes of the resonators lead to good sound insulation properties of the plate type structures. By combing different types of resonators together, enhancement of STL in wide frequency ranges can be achieved. The results in this paper provide good guidance for noise control in engineering applications.