A Worst-Case Approach for On-Line Flutter Prediction

Lind, Rick C. and Brenner, Martin J. (1998) A Worst-Case Approach for On-Line Flutter Prediction. Technical Report NASA/TM-1997-207056, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

Worst-case flutter margins may be computed for a linear model with respect to a set of uncertainty operators using the structured singular value. This paper considers an on-line implementation to compute these robust margins in a flight test program. Uncertainty descriptions are updated at test points to account for unmodeled time-varying dynamics of the airplane by ensuring the robust model is not invalidated by measured flight data. Robust margins computed with respect to this uncertainty remain conservative to the changing dynamics throughout the flight. A simulation clearly demonstrates this method can improve the efficiency of flight testing by accurately predicting the flutter margin to improve safety while reducing the necessary flight time.

EPrint Type:	NASA Technical Memorandum
Keywords:	Aeroelasticity, Structural Dynamics, Flutter, Structured Singular Value, Robust Stability, Flight Test
Subjects:	(01 - 09) Aeronautics: (05) Aircraft Design, Testing And Performance
ID Code:	1835
Deposited On:	12 Febuary 2008
Additional Information:	8 pages. Lind, Brenner, NASA Dryden Flight Research Center. Also presented at the CEAS International Forum on Aerostability and Structural Dynamics, Rome, Italy, June 1998.