Ship Vibration and Noise Reduction with Metamaterial Structures

Metamaterials and metamaterial structures show excellent performance in vibration reduction and energy absorption. The developments on modelling theories and additive manufacturing technology have enable the application of metamaterials to vibroacoustics design of ships. In this paper, metamaterial structures with auxetic effect and negative stiffness are designed to decrease vibration, underwater noise radiation and shock in naval structures. Functional element topology optimization (FETO) method to design lightweight metamaterials with Negative Poisson’s ratio(NPR), Negative Stiffness (NS) lattice metamaterals design by prefabricated buckling component method (PBCM) are introduced. A lightweight auxetic cellular vibration isolation base and a novel floating raft structures constituted by re-entrant hexagonal honeycombs showed the effect of vibration reduction in a geophysical vessel. A multilayer negative stiffness shock isolation base for marine structure show the application potentials of shock absorption of metamaterial structures. By replacing the conventional ribs with auxetic metamaterial rib in the submarine power equipment cabin between the double shell, the radiated sound power level and sound radiation directivity of a submarine are designed. Energy from power equipment can be blocked by using of auxetic metamaterial ribs.