Gomes C., Gerges S.

Nowadays, acoustic comfort is an important consideration in the design and operation of airplanes. The acoustical fields generated around an aircraft in flight act on the mid and high frequency regions, where the high modal density of the structure hinders dynamics analysis through deterministic methods. In this context, the search for effective methodologies to model vibro-acoustic characteristics at high frequencies has been the motivation for several scientific studies. As an alternative approach, Statistical Energy Analysis (SEA) allows the study of energy diffusion in vibro-acoustic systems at mid and high frequency regions. SEA results in a procedure for calculating the flow and storage of dynamical energy in a complex system. This present work describes the characterization of vibro-acoustic phenomena of a structure similar to an aircraft fuselage. Several SEA models were considered to compare the analytical formulations found in literature with experimental measurements. The measurements were carried out in two adjacent reverberation rooms which permitted an evaluation of the sound transmission loss and the vibration level of the panels: simple and ribbed-stiffened panel. The results show that SEA modeling provides a good prediction of the vibro-acoustic performance of single and ribbed-stiffened panels. Based on this, the importance of an accurate evaluation of resonant and non-resonant SEA parameters is pointed out. In this regard, the revised model for computing the coupling loss factors was evaluated and the results gave a much better agreement with measured data than the results from the SEA commercial software. The main contributions of this work are the detailed analysis of the hypotheses adopted during the SEA subsystems definitions and an accurate prediction of the vibro-acoustic phenomena through SEA models in single and ribbed-stiffened panels in the mid and high frequencies regions.