Objectives The inter-ship structure between double-layer shells is an important bridge for the transmission of acoustic vibration from pressure shell to light shell. To reduce the impact on the vibration acoustic radiation level of ships, the inter-ship structure of double-layer acoustic bridge is proposed and its acoustic vibration transmission characteristics are studied.
Methods The finite element method is used to establish the finite-length double-layer cylindrical shell vibration acoustic radiation model of the inter-board double-layer acoustic bridge. The difference between the sound and vibration transmission of the double-layer acoustic bridge and the traditional single-layer acoustic bridge structure is compared and analyzed. The influence of double-layer acoustic bridge structure, structural parameters and axial distribution spacing on acoustic radiation and vibration transmission characteristics is revealed.
Results The results show that the double-layer acoustic bridge connection structure between double cylindrical shells has better noise reduction effect than the traditional single-layer acoustic bridge structure. The effect of " 2-1" double-layer acoustic bridge structure model on reducing vibration transmission between double cylindrical shells is better than that of "1-2" and "2-2" double-layer acoustic bridge structures. Three different "1-1" double-layer acoustic bridge connection structures show similar effect on reducing vibration transmission. The spacing of the bottom acoustic bridge ribs and the width of the transverse plate have a great influence on the vibration transmission reduction effect of the double-layer shell structure, and the height of the acoustic bridge has little effect on the vibration transmission reduction effect of the double-layer shell structure. The closer the axial distribution of double-layer acoustic bridges between double cylindrical shells is, the worse the effect of reducing vibration transmission is.
Conclusions The research results can provide reference for the shock absorption and noise reduction design of ship's inter-board structure.