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Technical paper introduced by Becchis Osiride at SAE 2007 Noise and Vibration Conference - Identification of modal parameters

18 maggio 2007

Becchis Osiride published and introduced a technical paper about NHV measurement technique at the SAE 2007 Noise and Vibration Conference and Exhibition held in St. Charles, Illinois (USA, 15-17 May, 2007

SAE2007: the newest research, technologies, techniques, and trends to identify, measure, and eliminate noise, vibration and harshness. More than 25 sessions will feature over 250 SAE Technical Paper presentations covering:

•    Engine/Powertrain/Driveline

•    Passive and Active NVH Control

•    Vehicle Subsystems

•    NVH Measurement

•    Standards, Processes and Perspectives

•    Heavy Vehicle and Vehicle Exterior

•    Numerical Methods

(reference: http://www.sae.org/events/nvc/ )

 

Wednesday, May 16 - NVH Measuremet: facilities (Code: NVC15)

The session is focused on the development and application of facilities to conduct noise and vibration measurements. The intent is to provide practical information on the engineering challenges to consider in the construction and/or adaptation of a facility to the specialized noise and vibration requirements.

IDENTIFICATION OF MODAL PARAMETERS IN FREQUENCY DOMAIN WITH EMPHASIS ON OUTPUT ONLY CROSS- SPECTRAL DENSITY FUNCTIONS

This paper presents a technique for extracting modal parameters of a linear multi degree of freedom system in the frequency domain. The roots of the technique are the well known rational fraction polynomials method but emphasis is given to the application to output-only data in the form of cross-spectral density functions. A discussion is presented on the possibility of achieving reliable results also for structures undergoing multiple input excitations. Numerical stability of the technique is obtained by properly scaling both the frequency and the cross-spectrum axes.

Good performance of the method are shown for numerical examples and for a test case on an actual structure.