Abstract: Replace the added structure steel shell with acoustic stealth sandwich composite, the acoustic models of underwater acoustic stealth sandwich composite structure was built. The corresponding transition matrixes, reflection coefficient and absorption coefficient of oblique incidence in planar were deduced from the acoustic wave equation. The acoustic frequency response of stealth added structure with water layer in vertical incidence was measured by experiment, and the results of transition matrix method were matched to the experimental data. The influence in different oblique incidence angle was analyzed. The effects of acoustic stealth on the thickness, density, loss factors of absorption layer and the thickness of water were calculated, the acoustic stealth structure of underwater sandwich composite added structure was designed, and the reflection coefficient and absorption coefficient frequency response were analyzed by numerical method in different material parameter and different geometrical parameter.

Keywords：acoustic stealth; oblique incidence; sandwich composite; added structure; transition matrix