A numerical study of the acoustic performance of a metamaterial cylindrical shell based on the water-structure-air coupling relationship

Cylindrical shell structures in deep-sea equipment experience forced vibrations when subjected to external excitations. Local resonance metamaterials (LRMs) are capable of absorbing vibration energy, thereby reducing the transmission of acoustic power. This paper presents the design of an LRM based on Archimedean chiral spiral beams. The proposed metamaterial effectively absorbs the energy of forced vibrations in cylindrical shells, leading to excellent sound transmission loss (STL) performance. The vibrational transmittance of the metamaterial is calculated for both flat and curved plates. A three-dimensional acoustic-structural coupling computational model for LRM cylindrical shells is developed to investigate STL performance under varying structural parameters, material parameters, and hydrostatic pressures. The results demonstrate that the Archimedean chiral spiral local resonance metamaterial (ACSLRM) significantly improves STL at different depths across the bandgap frequency range and modulates the STL performance by changing the structural and material properties. This study explores the potential applications of ACSLRM in deep-sea environments and aims to provide valuable insights for the multifunctional design of LRMs.