Computational elastoacoustics of uncertain complex systems and experimental validation

Christian Soize (1) , C. Chen (2) , J.-F. Durand (2) , Denis Duhamel (3) , L. Gagliardini (4)

1 Mechanics
2 MSME - Laboratoire de Modélisation et Simulation Multi Echelle
3 Dynamique des structures et identification
4 PSA Peugeot Citroen

The paper deals with the robustness of uncertain computational elastoacoustic models in low- and medium-frequency ranges. The elastoacoustic system is made up of a heterogeneous viscoelastic structure coupled with an internal acoustic cavity filled with a dissipative acoustic fluid. A reduced mean elastoacoustic model is deduced from the mean finite element model by using the modal approach with the structural modes of the structure and the acoustic modes of the acoustic cavity. Data uncertainties and model uncertainties are taken into account by using a nonparametric probabilistic approach for the structure, for the acoustic cavity and for the vibroacoustic coupling interface. The main objectives of this paper are (1) to present experimental validation of the nonparametric probabilistic approach of model uncertainties and to propose methods to perform the experimental identification of the probabilistic model parameters, (2) to analyze the robustness of computational elastoacoustic models with respect to model and data uncertainties, (3) to study uncertainty propagation through complex elastoacoustic systems. Two experimental configurations are analyzed with the stochastic computational elastoacoustic model. The first experimental configuration is made up of a composite sandwich panel coupled with an acoustic cavity constituted of a simple rigid box. Experimental measurements have been performed for 8 manufactured composite panels. The second experimental configuration is a car made up of a complex heterogeneous structure coupled with a complex acoustic cavity. Experimental measurements have been performed for 22 manufactured cars of the same type with optional extra.

Mots clés: uncertainty quantification; computational vibroacoustics; computational elastoacoustics; nonparametric probabilistic approach; random matrix; modeling errors; model uncertainties; vibroacoustics; structural acoustics; vibrations; sounds; automotive vehicle

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]; Vibrations [physics.class-ph]; Vibrations [physics.class-ph]; Probabilités [math.PR]; Statistiques [math.ST]; Théorie [stat.TH]

Christian Soize, C. Chen, J.-F. Durand, Denis Duhamel, L. Gagliardini. Computational elastoacoustics of uncertain complex systems and experimental validation. (Semi-Plenary Lecture) Compdyn 2007, Jun 2007, Rethymno, Greece. pp.Pages: 71-84. ⟨hal-00684640⟩