Flutter analysis of high-aspect-ratio wings based on a third-order nonlinear beam model

Abstract

In this study, the effects of geometric structural nonlinearity on flutter of high-aspect-ratio wings are examined. The aeroelastic model used is based on (a) a set of governing differential equations describing the motion of an inextensional beam, previously formulated and (b) the semiempirical ONERA aerodynamic model. Galerkin method is implemented to solve dynamic perturbation equations about a nonlinear static equilibrium state. The small perturbation flutter boundary is determined by these perturbation equations. The effect of geometric structural nonlinearity of the beam model on the flutter behavior is significant. Especially, static deformations in the flapwise direction caused by a static force generally decrease system’s flutter speed and frequency.