Finite-Element Analysis of Vibration and Flutter of Cantilever Anisotropic Plates

The hybrid stress finite element method is used to study the effects of filament angle, θ, and orthotropicity parameter, EL/ET, on the vibration and flutter characteristics of cantilevered anisotropic plates. The results indicate a generally strong lack of monotonic dependence on θ. Also, the natural frequency in certain cases involving the first few modes, can become relatively insensitive to both θ and EL/ET for a range of θ beyond 70 deg. Values of critical dynamic pressure are obtained by a modal approach, in which the mode shapes are obtained by the hybrid stress method. Convergence of the modal method is rather rapid for the configurations analyzed, and a comparison of the method with an exact solution for the case of an isotropic simply supported plate shows that use of six modes gives excellent agreement.