Analysis of characteristics of sound radiation from double cylindrical shell coated with viscoelastic layer

The characteristics of vibration and sound radiation from a double shell with the outer shell coated with viscoelastic layer are systematically studied. The shell‘s motion function is expressed by the classical Fliigge operator and the layer‘s motion function is described by three-dimensional Navier equations, whose displacement solutions are expressed by Taylor expansion along the layer thickness. The continuity conditions of displacement and stress between the shell and the layers are used in obtaining the vibration equations. The effects of layer thickness, modulus of elasticity, the loss factor, and the hydro-compressibility on the structural acoustic characteristic are discussed in detail. It showed that the higher the modulus of elasticity is, or the thinner the thickness of layer is, or the smaller the loss factor is, the higher the sound radiation power is.