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Aiming to solve pass by noise issues, where the exhaust system is the main source, a bench test was built. It was based on an impedance tube method to measure the transmission loss of exhaust systems of vehicle combustion engines. The test bench reduces time on investigation of acoustic performance of exhausts systems and does not depend on weather conditions. The results were used to compare several proposals under investigation before assembling on the vehicle and also to give a comparable metric for validating numerical simulation modeling and analysis procedure. This paper describes the problems involved in the construction of the evaluation system. Three types of noise source were evaluated, considering pink and white noise.

In the last years, vehicle vibroacoustics has expanded as a basic and applied research area. Structural dynamic methods and technologies have been used with great success by the automotive industry. Experimental modal analysis is the process of determining the modal parameters (modes, frequencies and damping factors) of a linear system. This work presents the modal analysis of the Amazon family cars in full vehicle configuration (drivable units). A full vehicle represents a more complex system when compared to the body only, due to the systems attached to it, increasing its damping and measurable noise, and including coupled local and global modes.