NONLINEAR STRUCTURAL AND AEROELASTIC ANALYSIS OF HALE AIRCRAFT

Abstract

In this work, the static and dynamic aeroelastic behavior of high aspect ratio wings undergoing large static deformations has been investigated analytically and numerically. Towards this end, a geometrically exact nonlinear structural model based on a one-dimensional beam theory originally developed by Minguet and Dugundji [1] is used. An efficient evaluation of the static deformation of the entire High-Altitude Long-Endurance (HALE) airplane is then developed by adopting the single beam model to each substructure and merging them all together. Then, the thesis investigates the static aeroelastic performance of the wing by coupling the beam model with three aerodynamic models. The small and large amplitude dynamic behaviors of the wing about largely deformed position are analyzed to investigate the influences of both large static deflections and large amplitudes. In addition, large amplitude limit cycles (LCOs) are studied by combining the structural model with a Doublet Lattice Method (DLM). The LCO is solved using harmonic balance process and the numerical results indicate the effects of the nonlinear static deflections and amplitude magnitude.