Type of Document	Dissertation
Author	Eldred, Lloyd B.
URN	etd-10242005-174006
Title	Sensitivity analysis of the static aeroelastic response of a wing
Degree	PhD
Department	Aerospace Engineering
Advisory Committee	Advisor Name Title Kapania, Rabesh K. Committee Chair Haftka, Raphael T. Committee Member Johnson, Eric R. Committee Member Librescu, Liviu Committee Member Mason, William H. Committee Member
Keywords	Airplanes Wings Testing. Aerodynamic measurements.
Date of Defense	1993-02-05
Availability	restricted
Abstract A technique to obtain the sensitivity of the static aeroelastic response of a three dimensional wing model is designed and implemented. The formulation is quite general and accepts any aerodynamic and structural analysis capability. A program to combine the discipline level, or local, sensitivities into global sensitivity derivatives is developed. A variety of representations of the wing pressure field are developed and tested to determine the most accurate and efficient scheme for representing the field outside of the aerodynamic code. Chebyshev polynomials are used to globally fit the pressure field. This approach had some difficulties in representing local variations in the field, so a variety of local interpolation polynomial pressure representations are also implemented. These panel based representations use a constant pressure value~ a bilinearly interpolated value, or a biquadratic ally interpolated value. The interpolation polynomial approaches do an excellent job of reducing the numerical problems of the global approach for comparable computational effort. Regardless of the pressure representation used, sensitivity and response results with excellent accuracy have been produced for large integrated quantities such as wing tip deflection and trim angle of attack. The sensitivities of such things as individual generalized displacements have been found with fair accuracy. In general, accuracy is found to be proportional to the relative size of the derivatives to the quantity itself.
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