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Statistical Energy Analysis (SEA) is widely used for modeling the vibro-acoustic response of large and complex structures. SEA makes simulations practical thanks to its intrinsic statistical approach and the lower computational cost compared to FE-based techniques. However, SEA still requires underlying models for subsystems and junctions to compute the SEA coefficients which appear in the power balance equations of the coupled system. Classically, such models are based on simplified descriptions of the structures to allow analytical or semi-analytical developments. To overcome this limitation, the authors have proposed a general approach to SEA which only requires the knowledge of impedances of the structures to compute SEA coefficients. Such impedances can always be computed from an accurate FE model of each component of a coupled system.

During the design phase of a vehicle, it is important to have a simulation tool, which allows to make multiple runs and check the sensitivity of the acoustic response to several trim configurations with a quick turnover time. The Statistical Energy Analysis (SEA) is widely used to investigate such problems for airborne excitation. For structure-borne excitation, classical methods based on a simplistic modeling of the trim using 1D oscillators and non-structural mass are not accurate enough to capture the actual behavior of the trim. On the other hand, a detailed Finite Element-Poroelastic Element Method (FE-PEM) modeling strategy of the trim may be time consuming. Besides the large number of degrees of freedom required to accurately model dissipative materials (e.g. poroelastic), a FE-based approach also needs a preprocessing phase where each layer of the trims must be carefully meshed.

The need for the industry to simulate and optimize the acoustic trim parts has increased during the last decade. There are many approaches to integrate the effect of an acoustic trim in a finite element model. These approaches can be very simple and empirical like the classical non-structural mass (NSM) combined to a high acoustic damping value in the receiver cavity to much more detailed and complex approach like the Poro-Elastic Materials (PEM) method using the Biot parameters. The objective of this paper is to identify which approach is the most appropriate in given situations. This article will first make a review of the theory behind the different methods (NSM, Impedances, Transfer Matrix Method, PEM). Each of them will be investigated for the different typical trim families used in the automotive industry: absorber, spring/mass, spring/mass/absorber.

This paper presents new advances in predicting wind noise contribution to interior SPL in the framework of the Wind Noise German Working Group composed of Audi, Daimler, Porsche and VW. In particular, a new approach was developed that allows to fully describe the wind noise source using CFD generated surface pressure distribution and its cross-correlation function and apply this source on an SEA side glass. This new method removes the need to use a diffuse acoustic field or several plane waves with various incidence angle to approximate the correct acoustics source character to apply on the SEA side glass. This new approach results are compared with results previously published which use more deterministic methods to represent the side glass and the interior of a vehicle.