Model updating considering damping effects

It is generally an issue to correctly represent damping in complex full vehicle FE models for low frequency NVH analysis. Damping can be included as modal damping, structural damping or viscous damping. These parameters have a great influence on the quality of the model, they help to reproduce the closest comportment of the structure as observed in the reality.

Measurements by testing allow extracting normal modes and modal damping from the measured responses of structures. The first step of a model correlation is the comparison of the computed normal modes with the experimental results. Reponses from computation and test (FRFs for instance) can also in a second step be analyzed and compared for each single component of the trimmed body structure and show differences in the stiffness, mass repartition and damping. A sensitivity study followed by an optimization can point out the potentials where damping could be adjusted. In a last step, new separate measurements for these components can lead to an updated model.

The Author

Charline Bonfils, EDAG GmbH & Co. KGaA
Antoine Guellec, AUDI AG

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