This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Extraction of Static Car Body Stiffness from Dynamic Measurements
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2010 by SAE International in United States
Annotation ability available
This paper describes a practical approach to extract the global static stiffness of a body in white (BIW) from dynamic measurements in free-free conditions. Based on a limited set of measured frequency response functions (FRF), the torsional and bending stiffness values are calculated using an FRF based substructuring approach in combination with inverse force identification.
A second approach consists of a modal approach whereby the static car body stiffness is deduced from a full free-free modal identification including residual stiffness estimation at the clamping and load positions. As an extra important result this approach allows for evaluating the modal contribution of the flexible car body modes to the global static stiffness values.
The methods have been extensively investigated using finite element modeling data and verified on a series of body in white measurements. The results are compared with the conventional static test bench measurements and have shown to deliver robust results, with similar accuracy, in a more efficient way in terms of testing time and costs.
CitationDeleener, J., Mas, P., Cremers, L., and Poland, J., "Extraction of Static Car Body Stiffness from Dynamic Measurements," SAE Technical Paper 2010-01-0228, 2010, https://doi.org/10.4271/2010-01-0228.
- Rediers B. Yang B. Juneja V. Static and dynamic stiffness: one test, both results IMAC Proceedings 1998
- Griffiths, D. Aubert, A. Green, E.R. Ding J. “A Technique for Relating Vehicle Structural Modes to Stiffness as Determined in Static Determinate Tests,” SAE Technical Paper 2003-01-1716 2003
- Reichelt M. Identifikation schwach gedämpfter Systeme am Beispiel von Pkw-Karosserien TU Chemnitz 2003
- Cuppens K. Sas P. Hermans L. “Evaluation of the FRF Based Substructuring and Modal Synthesis Technique Applied to Vehicle FE Data” Proceedings of the international seminar on modal analysis Leuven 2001
- MSC.Nastran Quick Reference Guide