Abstract:

In this paper a new idea to investigate flutter problem Is proposed, the new idea is that we may study only a tew modes of an aeroelastic system instead of studying the whole.In the light of it, an approach to analysing flutter characteristics, which combines the merit of graphic and analytic methods is presented. Also an optimal performance index with clear physical meaning. which can overcome some inherent drawbacks of linear quadratic technique, is developed. The paper has shown a numerical example of an elastic wing, and some comparison between this method and "v-g" method for calculating the critical point （Vf, Wf） are carried out as well.

Key words: flutter suppression, optimal control, stability