Calibration of the damping dispersion parameter in a non-parametric probabilistic approach

• Published in: Journal of sound and vibration 2009-07, Vol.324 (3), p.690-711
• Main Authors: Goller, B., Pellissetti, M.F.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Measurement and testing methods; Physics; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...)
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2009.02.039

Response predictions in structural dynamics are in general very sensitive to random uncertainties associated with the underlying predictive mathematical model. One way to capture parametric and model uncertainties consists in the construction of a non-parametric probabilistic model, in which the reduced structural matrices are replaced by random matrices. The uncertainties are introduced at a global level and controlled through one dispersion parameter each, for the mass, damping and stiffness matrix. In the present paper the role of the damping dispersion parameter is investigated, for the case in which the adopted non-parametric model is calibrated with respect to an existing parametric model. It is shown that in the non-parametric model the influence of the damping dispersion on the scatter in the frequency response is relatively small, if a calibration criterion based on matrix norms is used. A novel method for calibrating this non-parametric model is proposed, which enforces the same scatter of the frequency response function (FRF) at the first resonance frequency, in the parametric and the non-parametric model. A case study involving a satellite FE model shows that with this approach the FRF scatter of the non-parametric model reaches a level similar to that of the parametric model used for its calibration.