Aeroelastic analysis of composite rotor blades in hover

Abstract

The aeroelastic phenomena of a composite rotor blade in hover is investigated using a finite element method. A large deflection type beam theory is used for the one-dimensional global deformation analysis of the hingeless, isolated rotor undergoing arbitrary large displacements and rotations, but small strains. The sectional elastic constants of a composite box beam, including warping deformations, are determined from the refined cross-sectional finite element method. A two-dimensional, quasi-steady strip theory is applied for the aerodynamic calculation. Complete nonlinear equations are solved by the Newton-Raphson method to obtain an equilibrium position and the stability equations are linearized about this position. The modal approach method based on coupled rotating natural modes is used for the flutter analysis. The effects of fiber orientation and stacking sequences on the aeroelastic stability have been investigated. (C) 1997 Elsevier Science Ltd.