Achieving Enhanced Sound Insulation through Micromembranes-Type Acoustic Metamaterials

Abstract

Acoustic micromembranes (AμMs) are attracting more and more attention due to their unparalleled light weight but high sound transmission loss (STL) at low frequencies. Previous works showed that AμMs feature remarkable sound insulation compared to homogeneous plates with the same surface mass density, while some follow-up works claimed that the outstanding insulation capability of small AμMs samples disappears when the sample size grows. To uncover the working mechanisms underpinning the unique behavior of AμMs, in this paper, we present theoretical and numerical studies of AμMs that couple the vibrations of the supporting frame and the AμMs within the lattice. The results show how the global response in the STL of the AμMs assembly is related to the geometrical parameters of AμMs cells and the lattice. This study provides a theoretical foundation for designing a large-scale yet high-insulation assembly of AμMs, and paves the way for applying AμMs for blocking low-frequency noise.

Acoustic Metamaterials for Low-Frequency Noise Reduction Based on Parallel Connection of Multiple Spiral Chambers

“…In recent years, acoustic metamaterials (AMs) with subwavelength sizes have attracted much attention, such as the membrane AM [ 12 , 13 , 14 , 15 , 16 ], the Helmholtz AM [ 17 , 18 , 19 ] and the Fabry–Perot (FP) AM [ 20 , 21 , 22 , 23 ], which can gain excellent sound absorption characteristics in the deep-subwavelength noise frequency range. The membrane AM is usually composed of an elastic membrane and rigid disk.…”