This paper is an overview of a research program for nonlinear aeroelas
ticity of rotorcraft in forward flight conducted at Duke University an
d supported by the Army Research Office. Theoretical and experimental
investigations of rotor aeroelastic stability and nonlinear response a
re described. A flexible rotor blade model with geometrical and freepl
ay structural nonlinearities and the ONERA stall aerodynamic model are
considered. Analytical and numerical solutions of nonlinear mathemati
cal models and experimental methods for flutter and forced response in
a wind tunnel environment are discussed. Correlations between theoret
ical and experimental results are presented and some significant concl
usions are drawn. It is hoped that this paper will help provide improv
ed fundamental understanding of the nonlinear aeroelastic behavior of
rotorcraft.