High frequency energy flow analysis methods: Numerical implementation, applications, and verification.

摘要

The approximate vibrational and acoustical responses of structural-acoustic systems can be modeled based on vibrational energy concepts so that the general behavior and response level of the systems are easily identified in an average sense. Currently the main energy-based method is statistical energy analysis (SEA). An alternative approach, referred to as the energy finite element method (EFEM), has been proposed. One of the main objectives of this investigation is to find the essential relationship between the two methods and to develop a new approach for energy modeling of high frequency structural-acoustic systems. An EFEM0 technique has been developed from the energy flow analysis (EFA) equations using a finite volume method (FVM). The formulation produces apparent "coupling factors" for both continuous and discontinuous systems. The resulting systems of equations have a simple band matrix form similar to that of SEA equations. The EFEM0 can be applied to relatively heavily damped, strongly coupled systems where conventional SEA theory is not applicable.;The accuracy of the EFA and SEA methods has been analyzed in order to find the applicable thresholds of the two methods. The EFA and EFEM 0 have been extended to orthotropic plate systems. In the cases where the direct field is significant, a hybrid EFEM0 technique is proposed to improve the predictions. The EFEM0 and hybrid-EFEM 0 techniques have been verified numerically or experimentally for analytical systems and engineering problems. Finally, all these techniques are applied to a complex built-up system, a heavy equipment cab. The cab EFEM 0-SEA model is experimentally validated in this study.