Gupta, Abhineet2020-02-262020-02-262019-12https://hdl.handle.net/11299/211757University of Minnesota Ph.D. dissertation. December 2019. Major: Aerospace Engineering and Mechanics. Advisors: Peter Seiler, Gary Balas. 1 computer file (PDF); xii, 139 pages.The presence of aeroservoelastic effects in the flight dynamics of flexible aircraft presents significant challenges in terms of performance degradation and instability. In order to develop control system for such aircraft, an accurate flight dynamics model is needed. Developing such a model is an multi-disciplinary effort and re- quires theoretical and experimental knowledge and research. This thesis describes the development of the flight dynamics model of a small, flexible aircraft. Each step of the multi-stage process of the development of the flight dynamics model is described. The steps include designing and conducting vibration experiments on the aircraft for system identification of the structural dynamics and the devel- opment of a finite element model based structural model based on the acquired data. Aerodynamic models are developed and implemented using modifications of standard vortex and doublet lattice methods. The purpose of the modifications is to capture the geometric nonlinearity. The effects of these complex phenomena on the flight dynamics and instability (flutter) are analyzed. Mean axes based flight dynamics equations are utilized. These subcomponents are implemented in the simulation software SIMULINK to obtain the flight dynamics model. Flight tests are conducted to obtain data which is used to update the flight dynamics model by updating the aerodynamics model of the aircraft. A correction matrices based approach is used for this purpose. The resulting model has low computational cost but is capable of capturing complex behavior like geometric nonlinearities and un- steady aerodynamics. The low computational cost and modularity of the flight dynamics model makes it ideal for analysis of the effect of various kinds of aero- dynamics and structural phenomena. For example, the significant effects of the capturing the geometrically nonlinear aerodynamics on flutter characteristics of the aircraft are easily evaluated by this model without long, tedious and resource intensive computations. The model is also suitable for Monte-Carlo analysis to estimate the effect of various kinds of open-loop and closed-loop uncertainties.enAeroelasticityFlexible AircraftFlight DynamicsThesis or Dissertation