L. Eckert, B. Caesar

An analytical procedure for updating a finite element model using experimental modal data is described in this paper. The described update procedure iteratively corrects design parameters so that the eigenfrequencies and mode shapes of a mathematical model converge to the measured ones. Any input parameter of a Finite Element- (FE-) model can be used as design parameter. The objective is to minimize the weighted differences of measured and analysed eigenfrequencies and mode shapes with minimum changes of the design parameters. The in general nonlinear functions of the eigenfrequencies and modes w.r.t. the design parameter are linearized based on FE-sensitivity analyses. The new mode shapes are approximated as a linear combination of the initial mode shapes. The update procedure can be coupled with any FE-program. Any type of finite element may be used in the FE-model. The procedure is able to update the erroneous design parameters using incomplete and noisy test data. Incomplete means, that not all modes or eigenfrequencies in the interesting frequency range have been measured or only a small number of the degrees of freedom of the mathematical model has been measured. No condensation to the test degrees of freedom or expansion of the test modes to the analysis degrees of freedom is necessary. In this paper the update of a two dimensional beam frame work is shown using incomplete and noisy modal test data.

International Forum on Aeroelasticity and Structural Dynamics 1991, Aachen

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

DGLR-Bericht, 1991, 1991-06, International Forum on Aeroelasticity and Structural Dynamics 1991 Proceedings; S.247-256; 1991; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroelasticity

Bestellbar

1991