An aeroelasticity beam model for flexible multibody systems under large deflections

Abstract

Dynamic analysis of multibody systems is a subject of interest in a number of diverse disciplines. However, the modelling of multibody systems has only concentrated on structural dynamics so far. It is felt that there is another important class of problem needing to be simulated for multibody systems, especially in the aerospace industry: aeroelastic modelling for complex multibody systems. This paper presents a finite element aeroelasticity beam model as a first effort in developing a general multibody aeroelasticity model. A nonlinear finite element multibody structure dynamics model previously developed is further extended to a finite element aeroelasticity beam model in this paper. The aerodynamic loads are computed for a beam attached to a moving base using a two-dimensional quasi-steady thin airfoil theory, and is discretized by the finite element method. This general model can be used as a basic element to analyse the aeroelasticity problems of a beam and the aeroelasticity problems of some multibody systems by making use of the six rigid body degrees of freedom of the beam base. The algorithm is applied to evaluate the aeroelasticity stability of helicopter rotor blades in a companion paper.