Noncontact dynamic measurements of lightweight flexible aerospace structures in motion present several challenges. Achieving high frequency and high resolution measurements requires multiple registered metrology systems. Many noncontact measurement methods are based on the object staying aligned with the sensor. Yet sometimes the desired loading is a result of the motion interacting with struct...

The Galerkin projection method based on modes generated by the Proper Orthogonal Decomposition (POD) technique is very popular for the dimensional reduction of linearized Computational Fluid Dynamics (CFD) models, among many other typically high-dimensional models in computational engineering. This, despite the fact that it cannot guarantee neither the optimality nor the stability of the Reduce...

The eigenvalues of bridges with aeroelastic effects are commonly portrayed in terms of a family of frequency and damping loci as a function of mean wind velocity. Depending on the structural dynamic and aerodynamic characteristics of the bridge, when two frequencies approach one another over a range of wind velocities, their loci tend to repel, thus avoiding an intersection, whereas the mode sh...

In current bridge aeroelastic analysis frameworks, predictions of flutter instability and buffeting response to wind fluctuations are treated as two separate procedures. The flutter instability is analyzed through the solution of a complex eigenvalue problem, offering information on how the self-excited forces influence bridge dynamics, especially the modal damping, and eventually drive the bri...

An experimental model of a typical three degree-of-freedom airfoil section with composite control surface subjected to a two-dimensional, incompressible air-flow has been created. The flutter response of the system with both, a defect-free and with damaged control surfaces, were measured experimentally. An analytical model was implemented to predict the flutter response in the case of a defect-...

Aeroelasticity is a critical consideration in the design of gas turbine engines, both for stability and forced response. Current aeroelastic models cannot provide highdelity aerodynamics in a form suitable for design or control applications. In this thesis low-order, highdelity aerodynamic models are developed using systematic model order reduction from computational uid dynamic (CFD) methods. ...

Motivated by modeling blood flow in human arteries, we study a fluid-structure interaction problem in which the structure is composed of multiple layers, each with possibly different mechanical characteristics and thickness. In the problem presented in this manuscript the structure is composed of two layers: a thin layer modeled by the 1D wave equation, and a thick layer modeled by the 2D equat...

In 1957 the slender-delta type of configuration had been adopted in the U.K. as the most promising for a supersonic transport aircraft designed to cruise at about M = 2.0, and by 1959 one or two exploratory studies of the aeroelastic behaviour of such layouts had been made. Professor Etkin now suggested a mode of attack on the steady and quasi-steady aeroelastic problems, whereby such an aircra...

HIGH altitude, long endurance (HALE) aircraft offer capabilities found nowhere else in the spectrum of machine flight, but their design and analysis offers unique challenges. From their observation altitude above 50,000 ft, HALE systems can relay telecommunication signals, perform intelligence, surveillance, and reconnaissance (ISR) functions covering large swaths of land for extended periods o...