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...

This work presents the analysis of nonlinear aeroelastic time series from wing vibrations due to airflow separation during wind tunnel experiments. Surrogate data method is used to justify the application of nonlinear time series analysis to the aeroelastic system, after rejecting the chance for nonstationarity. The singular value decomposition SVD approach is used to reconstruct the state spac...

The problem of the determination of the subcritical aeroelastic response and flutter instability of nonlinear two-dimensional lifting surfaces in an incompressible flow-field via Volterra series approach is addressed. The related aeroelastic governing equations are based upon the inclusion of structural nonlinearities, of the linear unsteady aerodynamics and consideration of an arbitrary time-d...

The procedures to assess the critical aeroelastic state of an aircraft with the AESIM simulation method are described. The main innovation is the identification with MIMO-class methods which opens up possibilities for efficient usage of aeroelastic simulation methods. Experience with recent applications is reported. ANALYSIS OF COMPUTATIONAL AEROELASTIC SIMULATIONS BY FITTING TIME SIGNALS Micha...

The identification of nonlinear aeroelastic systems based on the Volterra theory of nonlinear systems is presented. Recent applications of the theory to problems in experimental aeroelasticity are reviewed. These results include the identification of aerodynamic impulse responses, the application of higher-order spectra (HOS) to wind-tunnel flutter data, and the identification of nonlinear aero...

The hypersonic aeroelastic and aerothermoelastic problem of a double-wedge airfoil typical cross-section is studied using three different unsteady aerodynamic loads: (1) third-order piston theory, (2) Euler aerodynamics, and (3) Navier-Stokes aerodynamics. Computational aeroelastic response results are used to obtain frequency and damping characteristics, and compared with those from piston the...

The Solar powered unmanned aircraft have a high-aspect-ratio wings because SPUAV must satisfy the requirement of long endurance and high lift-drag ratio. Therefore, the structure of SPUAV‘s wings are structurally very flexible. The very high flexible wing might have large deformation and many aeroelastic problems. In this paper have a static/dynamic aeroelastic analysis through CFD-CSD coupled ...

Research into gust interactions has shown significant potential for extracting energy from the atmosphere. Notably, improvements to gust-energy extractions have been be possible through aeroelastic tailoring. The present work uses a design-space exploration quantify specific structural parameters that provide greatest gains discrete and continuous fields. Using genetic algorithm full-factorial ...

AbstrAct: The Operational Modal Analysis technique is a methodology very often applied for the identification of dynamic systems when the input signal is unknown. The applied methodology is based on a technique to estimate the Frequency Response Functions and extract the modal parameters using only the structural dynamic response data, without assuming the knowledge of the excitation forces. Su...

High-Altitude Long-Endurance (HALE) aircraft have wings with high aspect ratios. During operations of these aircraft, the wings can undergo large deflections. These large deflections can change the natural frequencies of the wing which, in turn, can produce noticeable changes in its aeroelastic behavior. This behavior can be accounted for only by using a rigorous nonlinear aeroelastic analysis....