Locally resonant pressure-resistant meta-shell with accordion zero Poisson's ratio core for sound insulation and sound radiation suppression

The multi-functionalization of deep-sea submersibles is an important development trend of advanced marine technology, and the new shell material is one of the main design playgrounds. Recent mechanical metamaterials have the capability to prevent transverse displacements during unidirectional compression (when the Poisson's ratio is flexibly adjusted to 0) and precisely manipulate elastic/acoustic waves on a sub-wavelength scale through their inherent resonance characteristics. Therefore, the metamaterial is introduced into the shell core of underwater equipment or submersible structure, which has potential technical advantages. The pre-strain wave propagation characteristics of the considered models are obtained static and dynamic steps via the finite element method. The pressure-resistant, sound transmission and radiation properties of meta-shell sandwiched the metamaterial cores are then investigated. The results show that in comparison with a traditional zero Poisson's ratio (ZPR) honeycomb core, the proposed meta-shell with a novel ZPR metamaterial core can safely withstand hydrostatic pressures equivalent to depths of 1000 m with greater safety redundancy, while also achieving sound insulation and sound radiation suppression in the low-frequency range. This work successfully demonstrates an advanced design method for sound insulation and sound radiation suppression of shells.