Aero-elastic characteristics of tapered plate wings

In the present work an aero-elastic model is presented to study flutter and divergence of isotropic plate wings. A finite element model is subsequently developed to apply the theoretical model and predict the performance of plate wings. A divergence analysis is carried out using the finite element model combined with the vortex lattice method for aerodynamic load calculations. The flutter analysis is carried out using a finite element model combined with the doublet lattice method. The aerodynamic model is coupled to the structural model using the shape (interpolation) functions of the finite element model. Static condensation is used to express the finite elements' in-plane degrees of freedom in terms of the bending ones, hence reducing the number of the elements' degrees of freedom per node to three. A MATLAB code is developed to implement the proposed model using three-node triangular finite elements. The present model is validated using benchmark problems available in the literature, and the effects of taper ratio on both divergence and flutter speeds and flutter frequency are studied.