Aeroelastic Response of Swept Aircraft Wings in a Compressible Flow Field

NASA Langley Research Center, Hampton, VA 23681-2199.ABSTRACT ly ,The present study addresses the subcriticalaeroelastic response of swept wings, in various flightspeed regimes, to arbitrary time-dependent external lexcitations. The methodology based on the concept ofindicial functions is carried out in time and frequency l,,,m,,domains. As a result of this approach, the properunsteady aerodynamic loads necessary to study thesubcritical aeroelastic response of the open/closed loopaeroelastic systems, and of flutter instability, pn,#respectively are obtained. Validation of the aeroelasticmodel is provided, and applications to subcriticalaeroelastic response to blast pressure signatures are Nillustrated. In this context, an original representation of P.,,go.,the aeroelastic response in the phase - space isdisplayed, and pertinent conclusions on the implications rof a number of selected parameters of the system areoutlined, s ,_NOMENCLATURE S,_,X_a,, Dimensionless elastic axis position measuredfrom the midchord, positive aftc. Chord length of wing, normal to the elasticaxis, 2b.C_. Lift-curve slopeh, h0 Plunging displacement and its amplitude,respectivelyAerospace Engineer, Ph.D.Professor of Aeronautical and MechanicalEngineering, Department of Engineering Science andMechanics.* Senior Research Scientist, Senior AerospaceEngineer, Aeroelasticity Branch, Structures Division,Senior Member AIAA.Copyright © 2000 The American Institute of Aeronauticsand Astronautics Inc. All right reserved.

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