Supersonic flutter analysis of stiffened laminated plates subject to thermal load

Abstract

Flutter analysis of stiffened laminated plates has been performed. The purpose of this study is to analyze the flutter characteristics of stiffened plates subject to thermal load. The first order shear deformable plate and Timoshenko beam theories are used for the finite element modelling of a skin panel and stiffeners respectively. The von Karman non-linear strain-displacement relation is used to account for large deflections. First order piston theory is used for modelling aerodynamic loads. The Newton-Raphson iteration method and complex eigenvalue solver with the LUM/NTF approximation method are used to obtain the postbuckled deflection and flutter information respectively. The Guyan reduction method and mode tracing procedure are employed for an efficient analysis. The effects of various parameters, such as the stiffening scheme, lamination angle, boundary conditions, and temperature gradient on flutter characteristics are investigated through some numerical examples. From these examples, it can be shown that the selection of a proper stiffening scheme results in great improvements of flutter characteristics of laminated panels without introducing considerable weight penalty. (C) 1999 Academic Press.