Nonlinear Aeroelastic Response Analysis of Wing with Flared Folding Wingtip

Abstract

The use of flared folding wingtip (FFWT) for load alleviation has been considered in recent studies. Most studies analyzed FFWT based on the linear assumption and ignored the nonlinearity of large wingtip folding angle. In this paper, for FFWT, a nonlinear aeroelastic modeling method based on multibody dynamics and unsteady vortex lattice method (UVLM) is developed. For wing with free-float FFWT, equilibrium and gust responses are simulated, and the gust responses were compared to the results of wind tunnel test to verify the validity of this method. The simulation results show that the geometric nonlinearity of the wingtip has little effect on the main wing but obvious effect on the wingtip. For a wing with active wingtip, the responses excited by wingtip active folding are simulated and compared to the linear modal method, which shows that the nonlinearity has large effects on the wing, especially at low excitation frequencies, and may lead to occurrence of response frequencies different from excitation.