Predictions of the sound transmission loss of composite sandwich panels.

摘要

The sound transmission loss (STL) characteristics of composite sandwich panels are studied. The dynamical motion of the sandwich panel is formulated by the consistent higher-order sandwich plate theory (HSAPT), which considers both the antisymmetric (bending) and symmetric (dilatational) motions of the sandwich panel. The STL of infinitely large sandwich panels is first calculated using the classical theoretical formulation based on the impedance of the air and the impedances of the sandwich panel. To account for finite-dimension effect, a finite element method (FEM) and boundary element method (BEM) combined program is developed to calculate the STL of sandwich panels with finite dimensions. Considering the limitations of FEM and BEM at high frequencies, a statistical energy analysis (SEA) is utilized to numerically study the STL of sandwich panels, especially at high frequencies. All predictions are compared with the experimental data with acceptable agreements. Advantages of different approaches are discussed and conclusions are made.;The STL prediction tools are then used in a parametric study to determine effects of various design variables on the sound transmission loss of sandwich panels. Finally, an optimization technique to design a weight-optimized sandwich panel is developed using a genetic algorithm (GA), taking into consideration of both the acoustical and mechanical properties of the sandwich panel. The present approach illustrates how the methodologies can serve as practical design tool to optimize sandwich panel designs in terms of both sound insulation and mechanical properties.