Abstract:The sound absorption performance of polyurethane cavity wedges is of significant importance to vibration and noise reduction of sonar platform,the wedge material dynamic mechanical parameters of different temperature and sound absorption coefficient of different hydrostatic pressure are respectively tested through the experimental research.Wicket chart is introduced to screen the test data,and the material parameters are obtained in a broad band under a certain temperature by using the equivalence principle of time-temperature.Furthermore,the varying characteristics of sound absorption performance with temperature, frequency, and hydrostatic pressure are discussed.Based on the test data, the wedge’s sound absorption performance is optimized by applying optimum theory. The vibration and acoustic characteristics of sonar platform laying of polyurethane cavity wedge is discussed through application research.The vibration and noise reduction effects of new type polyurethane cavity wedges are verified.