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Virtual SEA: Towards an Industrial Process
Technical Paper
2007-01-2302
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
In the high frequency range, the SEA method has been applied to air borne path with success to predict both internal and external sound environment. Nevertheless, structure-borne prediction is still at issue -especially for cars, in the range 200 to 2000 Hz- as results are widely dependant on subsystem partition and validity of various assumptions required by SEA.
Experimental SEA test technique (ESEA), applied to car bodies, has brought to the fore that SEA power balanced equations could robustly describe structure-borne noise. To make ESEA predictive, the database of measured FRF is simply replaced and enlarged by synthesized data generated from a finite element (FE) model and a selected observation grid of nodes. This technique, called Virtual SEA (VSEA), has been presented at SAE/NVC 2003. Since then, many developments have been carried out to improve the general efficiency of the three main steps of VSEA:
- The generation of the band-integrated FRF database (between nodes of the observation grid) is now integrated in the virtual SEA solver. As several millions of band averaged FRF can be required for a full car body analysis, a specific fast FRF synthesis is performed using analytical integration and band-optimized solutions by limiting the number of cross-modal terms in the series solution.
- Automatic subsystem partition has been widely improved by developing different algorithms that limit the sensitivity of results to initial conditions.
- ESEA loss matrix identification process has been reviewed for better resolution of highly non homogeneous system such as car bodies. The normalization of squared FRF matrix by the input mobility matrix allows a direct determination of subsystems modal density. The dynamics of a very large 3D FE model can thus be compressed into a small SEA loss matrix while preserving local transfer information at all nodal observation points.
Examples of applications are shown on car components.
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Citation
Borello, G. and Gagliardini, L., "Virtual SEA: Towards an Industrial Process," SAE Technical Paper 2007-01-2302, 2007, https://doi.org/10.4271/2007-01-2302.Also In
References
- Borello G. “Identification of SEA Coupling Loss Factors on a liquid rocket engine” Inter-Noise 1991 Sydney, Australia
- Borello G. “Prediction and control of structure-borne noise transfers in vehicules using SEA” Euro-noise 4-7 October 1998 Munich, Germany
- Gagliardini L. Houillon L. Petrinelli L. Borello G “Virtual SEA: mid-frequency structure-borne noise modeling based on Finite Element Analysis” SAE-NVC 2003-01-1555 Traverse City, MI, USA
- Ohayon, R. Soize C “Structural Acoustics and Vibration” 1998 Academic Press
- Bathe K. J. Wilson E.L. “Numerical Methods in Finite Element Analysis” Prentice-Hall 1976 New York
- Maidanik G. “Response of coupled dynamic systems” Journal Sound Vib. 1976 46 561 583
- Mondot J.-M. Petersson B “Characterization of structure-borne sound sources, the source descriptor and the coupling function” Journal Sound Vib. 1987 114 3 507 518
- Lalor N. “The Experimental Determination of Vibrational Energy Balance in Complex Structures” Paper 108429 Proc. SIRA Conference on Stress & Vibration 1989 London
- Rosen M. Borello G “Damping and coupling loss factors estimation in SEA method: what is really measured?” Inter-Noise 1996
- Lalor N. “Experimental statistical energy analysis: a tool for the reduction of machinery noise” Presented to the E.J. Richards Memorial Session at the 131st ASA Meeting Indianapolis, USA May 1996
- SEA-XP User Guide Manual, InterAC Sarl, Version 2.6 October 2006
- Arfken G. “Cauchy's Integral Formula” §6.4 in Mathematical Methods for Physicists 3rd Orlando, FL Academic Press 1985
- Crosby Jack L. “Computer Simulation in Genetics” John Wiley & Sons 1973 London
- Durand J.-F. Gagliardini L. Soize C. “Nonparametric modeling of the variability of vehicle vibroacoustic behavior” SAE-NVC 2005-01-2385 Traverse City, MI, USA
- Manning Jerome E. “SEA Models to Predict Structureborne Noise in Vehicles” SAE-NVC 2003-01-1542 Traverse City, MI, USA