ABSTRACT
An analytical study is presented to predict noise transmission through nonlinear double wall sandwich panel systems subject to random loading. Viscoelastic and nonlinear spring dashpot models are chosen to characterize the behavior of the soft core. The noise transmission through this panel system is determined into an acoustic enclosure of which the interiors are covered with porous absorption materials. The absorbent boundary conditions of the enclosure are accounted for by a two-step transformation of the boundary effect into a wave equation which governs the acoustic pressure field. The nonlinear panel response and interior acoustic pressure are obtained by utilizing modal analyses and Monte Carlo simulation techniques. Numerical results include the nonlinear response time histories and noise reduction. It is found that by proper selection of the dynamic parameters and damping characteristics, the noise transmission can be significantly reduced by the double wall sandwich construction.
