Experimental Acoustic Modal Analysis of an Automotive Cabin

© The Society for Experimental Mechanics, Inc. 2015. In the automotive industry, one of the most important comfort requirements in designing a high quality vehicle is to avoid or minimize the noise in the passenger compartment. Therefore, an ever increasing interest exists to predict the interior acoustic behavior by means of accurate simulation models both to improve the vehicle NVH performance and to reduce the development cycle for new products. Nevertheless, nowadays the level of accuracy of such models is not sufficient to replace the design prototype phase with an all-digital phase, so experimental methods in which an acoustic characterization is performed based on measurements play an important role in understanding the modelling challenges, improving the overall modelling know-how and, more in general, in comprehension of the physical behaviour. By means of a case study on a fully trimmed sedan car, this paper discusses the acoustic modal analysis equipment requirements and testing procedure. Due to specific acoustic modal analysis challenges, such as the high modal damping ratios and the need to use a large number of sound sources spread around the cabin to get a sufficient excitation of the modes, the modal parameter estimation is often a non-trivial task. Here the modal parameters (i.e. resonance frequency, damping ratio, mode shape, and modal participation factor) will be estimated by the new ML-MM method, a multiple-input multiple-output frequency-domain maximum likelihood estimator based on a modal model formulation. The performance of the ML-MM method will be compared to more classical modal parameter estimation methods.

ISBN:978-3-319-15235-6

Publication year:2015

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Private, Higher Education