Optimal geometry of ABH-based honeycomb panels for vibro-acoustic control on board cruise ships

The control of both structure-borne noise and airborne noise is of paramount importance on board cruise ships. The international regulations limit the noise levels in the ship’s surroundings and internal spaces. Moreover, the classification societies release different comfort classes based on the noise levels ensured in the cabins, and of course, the owners would like to reach the highest class. For such reasons, researching innovative solutions to improve vibro-acoustic control onboard ships is of primary interest to the maritime industry. Honeycomb panels are usually used as soundproofing ceilings on board ships; therefore, this paper aims to increase their performance by embedding Acoustic Black Holes (ABH) in their geometry. The ABHs are a technology capable of capturing and reducing the vibrations of the structure on which they are applied. Different research reported in the literature demonstrates their efficiency and proposes some applications, for example, in the automotive sector. As the ABH effect depends not only on the ABH size but also on its shape, the most efficient ABH profile inside a honeycomb panel has been determined. The obtained results highlight the validity of the adopted procedure and give guidelines for the design of ABH-based panels to improve soundproofing on board cruise ships.