Abstract
Keywords: Flutter, vortex-lattice method, aeroelasticity, fluid-structure interaction, perturbation method, uncertainty.
This paper deals with the investigation of the influence of span-wise distribution of bending and torsion stiffness uncertainties on the flutter behavior of an aeroelastic wing using a stochastic finite element approach. The analysis adopted a numerical algorithm to simulate unsteady, nonlinear, incompressible flow (based on the unsteady vortex lattice method) interacting with linear aeroelastic structure in the absence of uncertainties. The air flow and wing structure are treated as elements of a single dynamical system. Parameter uncertainties are represented by a truncated Karhunen-Love expansion. Both perturbation technique and Monte Carlo simulation are used to establish the boundary of stiffness uncertainty level at which the wing exhibits flutter in the form of limit-cycle oscillations (LCO) and above which the wing experiences dynamic instability. The analysis also includes the limitation of perturbation solution for a relatively large level of stiffness uncertainty.