VIBROACOUSTIC CHARACTERISTICS OF DAMPED LAMINATED SHELLS AND PANELS

Laminated panels are being used increasingly widely in automotive applications because of their high strength-to-weight ratio compared to metallic materials. Their use in lightweight vehicles is thus beneficial in terms of emissions, but raises issues for noise and vibration performance. Modelling and design of laminated panels with complex layups is much more demanding than for more conventional structures, and damping effects are often neglected. In this paper the vibroacoustic characteristics of damped laminated panels are investigated in terms of wave propagation, energy flow and loss factor showing some significant effects of damping. In particular a formulation of the complex Poynting’s vector and an expression to evaluate the energy velocity for the general case of a viscoelastic anisotropic panel is obtained using a finite element model of just a small segment of the laminated panel. A numerical example concerning a curved viscoelastic laminated panel is shown in order to illustrate some results.