Study on the Low-Frequency and Broadband Sound Absorption Performance of an Underwater Anechoic Layer with Novel Design

To further improve the low-frequency broadband sound absorption capability of underwater anechoic layer (UAL) on surface marine equipment, a novel structure with cavities (NSSC) is designed by adding resonators and honeycombs to traditional (SSC). Based principle shear dissipation, original intention design allow more parts viscoelastic material participate dissipation acoustic energy. The approximate multilayer theoretical model based modified transfer matrix method used verify accuracy finite element calculations. In frequency range 1100 Hz–10,000 Hz, coefficient (α) NSSC can reach 0.8. effects presence size cylindrical oscillators honeycomb structures are discussed in detail. results show that expanding effective damping area key wideband effect. This concept could guide structural UAL.