Date of Award

Fall 1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical & Aerospace Engineering

Program/Concentration

Engineering Mechanics

Committee Director

Chuh Mei

Committee Director

Gene J.-W. Hou

Committee Member

Thomas E. Alberts

Committee Member

Duc T. Nguyen

Committee Member

Ptamote Dechaumphai

Committee Member

Charles P. Shore

Abstract

A frequency domain solution method for nonlinear panel flutter with thermal effects using a consistent finite element formulation has been developed. The von Karman nonlinear strain-displacement relation is used to account for large deflections, the quasi-steady first-order piston theory is employed for aerodynamic loading and the quasi-steady thermal stress theory is applied for the thermal stresses with a given change of the temperature distribution, ΔΤ (x, y, z). The equation of motion under a combined thermal-aerodynamic loading can be mathematically separated into two equations and then solved in sequence: (1) thermal-aerodynamic postbuckling and (2) limit-cycle oscillation. The Newton-Raphson iteration technique is used to solve the nonlinear algebraic equations and an updated linearized eigen-solution procedure is adopted to solve the nonlinear differential equations. The finite-element frequency domain solution results are compared with numerical time integration results. Limit-cycle responses, flutter boundaries, snap-through areas and stress distributions are obtained from the present analyses. The effects of different temperature distributions, panel aspect ratios and boundary support conditions are investigated.

The influence of temperature and dynamic pressure on panel fatigue life is also presented. The relation of dynamic pressure versus panel life time at a given temperature is established and an endurance and failure dynamic pressures on panel fatigue life can be estimated.

DOI

10.25777/m7g5-bn94

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