Acoustic stealth design of underwatersandwich composite added structure under oblique incidence

The acoustic model of underwater acoustic stealth sandwich composite structure was built. The corresponding transition matrixes, reflection coefficient and absorption coefficient under in-plane oblique incidence were deduced from the acoustic wave equation. The acoustic frequency response of stealth added structure with water layer under vertical incidence was measured by experiment, and the results of transition matrix method match well with the experimental data. The influence of different oblique incidence angles was analyzed. The effects of thickness, density, loss factors of absorption layer and thickness of water on the acoustic stealth performance were calculated, the acoustic stealth structure with underwater sandwich composite material was designed, and the frequency responses of reflection coefficient and absorption coefficient were analyzed by numerical method with different material parameters and different geometrical parameters.