Aplicação conjunta do método dos elementos finitos e da análise estatística de energia ao estudo vibroacústico de estruturas acopladas

Abstract

A methodology to characterize the vibro-acoustic behavior of panels has been developed. The Statistical Energy Analysis (SEA) was chosen having in mind typical engineering applications, particularly those often found in road and aerial vehicles. The objective is to develop a tool that provides the needed flexibility in both configuration and in the choice of parameters for the analyzed system. SEA was implemented combined with Finite Element Method (FEM) procedures in order to improve the ability to cope with a variety of different configurations, also taking into account the frequency range, SEA being the choice for high frequency problems. The methodology addresses the problem taking into account how the influencing parameters, e.g.: damping, modal density, boundary conditions and the excitation, modify the energy transmitted through the structure. The targeted focus was the determination of how flexural (bending) waves propagate through coupled structures, a crucial consideration in vibro-acoustic problems. The methodology has been implemented in a typical panel configuration for which experimental results from other authors were readily available, thus providing an additional validation means. The analyzed configuration consisted of two panels connected at 90 degrees using the so-called L junction, considering a line connection. Both wave approach and the experimental statistical energy analysis (ESEA) with FEM were used, in order to investigate the influence of the model parameters and for each chosen simulation condition, with respect to the transmitted energy level variables and the coupling factor. Airborne transmission analysis in the panel was also investigated, introducing the considerations related to different transmission paths associated with the coupling factor. Finally, the proposed methodology enables the determination of how the configuration and simulation procedure affect the results hopefully providing a useful analysis and design vibro-acoustic tool.