سال انتشار: ۱۳۸۶

محل انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک

تعداد صفحات: ۷

نویسنده(ها):

Haftchenari – Associate Professor, Faculty of Engineering,Guilan University, Rasht, Iran
Moslemi – M. Sc. Student, Faculty of Engineering, Guilan University, Rasht, Iran
Farjad – M. Sc. Student, Faculty of Engineering Guilan University, Rasht, Iran

چکیده:

A frequency domain method is presented for determining the nonlinear flutter characteristics of a simply supported two-dimensional panels usingfinite element approach and applying unsteady third-order piston theory aerodynamics. Both nonlinear (largeamplitude) structural and nonlinear aerodynamic terms are considered in the finite element formulation. By eliminating the nonlinear terms in the aerodynamics equations, the linear part of aerodynamics and nonlinear structural finite element results are obtained and compared with existing solutions. Solution procedures are presented to solve the nonlinear panel flutter finite element equations. It is seen that finite element results using LUM/NTF (Linearized Updated
Mode with a Nonlinear Time Function Approximation Method) linearizing method agree well with classical and analytical solutions. Also it is shown that with considering the vanishing of damping ratio instead of coalescence of first two eigenvalues as stopping criteria in the related program, the instability sets in at a somewhat higher value of λ. Results are also different for different signs of the amplitude of the panel by
applying third order piston theory aerodynamics.