Research on noise prediction and acoustics design of shipboard cabin

The approach used to calculate structure surface vibration velocity and sound pressure level (SPL) is provided. Then structural vibration model and panels acoustic contribution are combined to investigate sound radiation from a vibrating structure. As for the shipboard cabin where the mariners work with high level requirement of the SPL, it's necessary to build the boundary element model of shipboard cabin by obtaining the structural mode information and finding out characteristics of vibration velocity. Considering the effect of thin-shell-structure consoles and switchboards, the acoustic field inside the shipboard cabin and the panel contribution to the cabin are analyzed. The peak frequencies in the sound pressure spectrum at the field points and their corresponding panels with larger contributions to the cabin are found. Based on the modal shape analysis, damping is adopted to inhibit the predominant modes. In front of the console and the switchboard where the engineer on watch operate, at the height of one's head with sitting posture and standing posture, four field points are laid out respectively. Then, the most obvious peak frequency is picked out as the frequency of attention. Vibration reducing measures like laying damping coatings and modular floating floors and so on are adopted to reduce the noise radiation of the plate in the ship cabin. Through the deck vibration transmission experiment, the damping performance of the modular floating floor is ascertained. A comprehensive assessment of the noise label in the cabin is needed to ensure that the sound pressure level meet the relevant requirements of the ship general rules.