A Spectral Method for Fast Broadband Insertion Loss Modeling of Curved Sound Packages: Correlation with Poroelastic Finite Elements

SEA or hybrid/virtual SEA approaches are often used for interior noise prediction of fully trimmed vehicles in the middle and high frequency range. Experimentally, a dependence of the Insertion Loss slopes of noise treatments following the curvature is observed. Thus, such vibroacoustic simulation approaches require trim Insertion Losses recomposed from a database of pre-computed equivalent curvature cases carried out with poroelastic finite elements in the middle frequency only. Indeed, one of the remaining difficulties is to perform accurate broadband Insertion Loss simulation of any curved sound packages. A lot of research has focused on modeling specific problems: stiffened shells, poroelastic cylinders, viscoelastic sandwich systems, etc. A unified approach is proposed here allowing the construction of a vibroacoustic model for a multi-layered cylindrical system of arbitrary nature. In particular, this system can be composed of orthotropic shells, 3D viscoelastic solids or 3D poroelastic media. The spectral nature of the approach makes it possible to cover medium to high frequency range for industrial size systems in a fast manner. Correlation results between poroelastic finite elements BEM-FEM Insertion Loss simulation up to 2,5 kHz and the proposed cylindrical TMM simulations up to 8 kHz will be presented, as well as experimental measurements.