Experimental Study on Sound Insulation Characteristics of Embedded Co-Cured Composite Damping Structures

Using IIR rubber as the main material of visco-elastic damping component,the specimen of damping membrane was made by compressive molding.According to the cure curves,some specimens of embedded co-cured composite structure were made by using glass-fabric reinforced epoxy plies.Finally,standing-wave-tube method was used to study its sound insulation properties.Test results show that by adding a thin damping layer,damping of the specimen can be increased without obvious stiffness change,and the low-frequency sound insulation property is improved.When adding a thick damping layer,the property of sound insulation of the specimen is not sensitive to the change of the thickness of the damping layer.The increasing of sound insulation of the specimen is mainly due to the increase of the stiffness and the mass of the specimen.Therefore,it is inappropriate to improve the sound insulation property of the structure by increasing the thickness of the damping layer of the embedded co-cured composite damping structures.