This paper presents an integrated flight dynamic modeling method for flexible aircraft that captures coupled physics effects due to inertial forces, aeroelasticity, and propulsive forces that are normally present in flight. The present approach formulates the coupled flight dynamics using a structural dynamic modeling method that describes the elasticity of a flexible, twisted, swept wing using...

This paper presents results for the aeroelastic stability and LCO behavior for a complete aircraft. Comparison are presented between the results predicted by a cantilevered wing model, an untrimmed aircraft model (no gravity or drag) and a trimmed aircraft model. It is seen that the stability behavior is predicted accurately only if the correct trim loads are applied to the wing. The LCO behavi...

Having the constant population size and crossover/mutation probability, standard genetic algorithm (SGA) has such disadvantages as premature convergence, low stability and optimization efficiency for large design variables situation. This paper presents an improved adaptive genetic algorithm (IAGA), which adjusts the population size and the crossover/mutation probability adaptively and linearly...

This paper analyses the accuracy and numerical stability of coupling procedures in aeroelastic modelling. A two-dimensional model problem assuming unsteady inviscid ow past an oscillating wall leads to an even simpler one-dimensional model problem. Analysis of different numerical algorithms shows that in general the coupling procedures are numerically stable, but care is required to achieve acc...

Two 2-D aeroelastic models are presented here to determine instability boundary (flutter speed) and gust response of a typical section airfoil with degrees of freedom in pitch and plunge directions. To build these 2-D aeroelastic models, two different aerodynamic theories including Indicial Aerodynamic Theory and Vortex Lattice Method (VLM) have been employed. Also, a 3-D aeroelastic framework ...

A method is presented for the stress analysis of flight vehicles under different flight conditions including gust and control surface deflection (or maneuver) using the governing equations of rigid-body motions and elastic deformations. The Lagrangian approach is used to derive the governing equations of motions. For this purpose, the basic equations of motions are derived in terms of potential...

System identification is used to develop an accurate and computationally efficient discrete-time aerodynamic model of a three-dimensional, unsteady CFD solution. This aerodynamic model is then used in place of the unsteady CFD solution in a coupled aeroelastic analysis resulting in a substantial savings in computational time. The methodology has the advantage of producing an explicit mathematic...

Methods for structural design, control, and testing of flexible aircraft structures are considered. Focus is on nonconventional aircraft configurations and control concepts. The interaction between analysis and testing is a central topic and all studies include validation testing and comparison between computational and experimental results. The first part of the thesis is concerned with the de...

In engineering practice, eigen-solution is used to assess the stability of linear dynamical systems. However, linearity assumption in systems sometimes implies simplifications, particularly when strong nonlinearities exist. this case, eigen-analysis requires linerisation problem and hence fails provide a direct estimation. For reason, more reliable tool should be implemented predict nonlinear p...