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The automotive vehicle is a system of high complexity in relation to the generation sources of noise and vibration. In order to achieve the overall vehicle NVH objectives, the damping treatment of the body panels needs to be optimized. Therefore the objective of this study is to compare the characteristics of two materials of floorpan treatments (deadeners): an asphalt melt sheet (bitumen pads) and a waterborne material (LASD - Liquid Applied Sprayable Damper - AcusticCol).

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.

For the automotive industry, the sound quality inside the vehicles is very important. This importance has increased significantly in the last years within the globally competitive automotive market. The interior vibroacoustic behavior depends on the dynamic characteristics of the car body. Several treatments are used to reduce the structural energy of the body panels. For instance, it may be applied passive damping technology, by use of viscoelastic materials, to control their noise and vibrations. This paper presents a comparison of the vibroacoustic characteristics of two firewall panels, made with normal and quiet steel. Experimental and numerical (FEM and BEM) techniques are used to get modal and acoustic data.

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.

During the last years, the automotive industry dedicated great efforts to understand and solve the noise problem from disc brake systems. There are several types of brake noise problems, each one related with a frequency range of occurrence. In most cases, the customer perceives the noise as a vehicle problem and demand having it fix by their dealer. As a consequence, disc brake noise is one of the major contributors to the automotive manufactures warranty costs, leading the automotive industry to look for ways to control it. A large class of disc brake noise problems is associated with the resonant behavior of an operating brake system. However, the detection of these brake system modes during the operating condition can be very expensive, demanding the use of inertial dynamometers and laser vibrometer measurements.