Bending-Torsion Flutter of an Airfoil with Nonlinear Structural Characteristics

Author: Peck, Jerry Clifford

Year: 1959

Degree: Engineer's thesis

Advisors: Sechler, Ernest Edwin; Caughey, Thomas Kirk

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/P0DS-PX18

Abstract

A theoretical analysis of the incompressible bending-torsion flutter of a two-dimensional airfoil with nonlinear structural characteristics is presented. The Method of Slowly Varying Parameters of Kryloff and Bogoliuboff is applied, and the steady-state oscillations are found. The stability of the steady-state oscillation is analyzed through the use of perturbation equations. A quasi-steady aerodynamic approximation is used, and closed-form solutions for the steady-state oscillations are found for the case of elastic torsional nonlinearities. A numerical example of a soft-hard stiffness characteristic is treated, and the steady-state and stability results given.

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