MATEC Web of Conferences
Volume 20, 2015AVE2014 - 4ième Colloque Analyse Vibratoire Expérimentale / Experimental Vibration Analysis
|Number of page(s)||6|
|Published online||27 January 2015|
New developments for experimental modal analysis of aircraft structures
1 Institut Supérieur de l'Aéronautique et de l'Espace, 10 avenue Edouard Belin, 31400 Toulouse, France
2 University of Poitiers, Laboratoire d'Informatique et d'Automatique pour les Systèmes, Bâtiment B25 – 2, rue Pierre Brousse, TSA 41105, 86073 Poitiers Cedex 9, France
This article presents an identification algorithm dedicated to the modal analysis of aircraft structures during flight-tests. More specifically, this algorithm was designed to process short duration tests carried out with multi-input excitations. The identification problem is solved in the frequency domain and the limit effects are considered so as to avoid transient effects with short data sequences. To minimise the effects of the noise, a non-linear gradient-based optimisation method is used. Its performance is improved by the use of an appropriate over-parametrised matrix fraction descriptions. Because the cost function to be minimised is non-convex, this method is however sensitive to the initialisation. For this reason, an iterative instrumental variable method is used to find an initial estimate. This one gives a value of the cost-function sufficiently close to its global minimum so as to ensure a fast convergence of the optimisation. Thus, the algorithm presented in this article is a combination of two iterative methods that gives accurate mode estimations even with high level of noise, as shown on an illustrative example.
© Owned by the authors, published by EDP Sciences, 2015
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.