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Vibration levels of structures can be significantly reduced by adding some damping materials to the vibrating surfaces. The viscoelastic behavior of these materials induces losses of kinetic energy when they undergo cyclic deformation. A good estimate of the damping loss factor is an important design parameter allowing the creation of efficient damping treatments. For Statistical Energy Analysis (SEA) purposes, the damping loss factor is usually estimated through the Power Injection Method (PIM). This paper presents the application of PIM to obtain the damping loss factor of a typical fuselage panel. In this case, the structure under study is a curved ribbed-stiffened panel. Tests are carried out for undamped and damped conditions. The added damping is provided by layers of viscoelastic material attached to the fuselage skin. The results show the applicability of the method for this kind of structure.

Nowadays, acoustic comfort is an important consideration in the design and operation of airplanes. In this context, an alternative approach, Statistical Energy Analysis (SEA) allows the study of energy diffusion in vibro-acoustic systems in mid and high frequency regions. This present study aims to describe the vibro-acoustic characterization of a structure similar to an aircraft fuselage. Several SEA models were considered to compare the analytical formulations found in the literature with measurement data. Two classes of the panels were investigated: simple and ribbed-stiffened. In this regard, the revised model for computing the coupling loss factors was evaluated and the results gave a good agreement with measured data.

Statistical Energy Analysis (SEA) is the standard method used to access noise and vibration levels in aircrafts and it has been applied to a wide range of problems in the aerospace industry. Even though much research has been carried on in the subject, some questions still remain about the process of modeling aircraft structures and the necessary validation steps. In this work, the development of a SEA model of a fuselage section is discussed. Special attention is given to the structure-borne noise transmission between the fuselage and floor panels and different modeling approaches are investigated. Data obtained through experimental tests were then used to verify the modeling approaches. It is seen that overall SEA results display a good agreement with tests. In the case of the floor panel, model results are very sensitive to modeling approaches and given that the transmission path is correctly represented, the SEA results reasonably match the experimental data.