Nonperiodic flutter of a buckled composite panel

The nonlinear vibrations of a composite panel subjected to uniform edge compression and a high-supersonic coplanar flow is analysed. Third-order piston theory aerodynamics is used and the effects of in-plane edge restraints, small initial geometric imperfections, transverse shear deformation, and transverse normal stress are considered in the structural model. Periodic solutions and their bifurcations are determined using a predictor-corrector type Shooting Technique, in conjunction with the Arclength Continuation Method for the static state. It is demonstrated that third-order aerodynamic nonlinearities are destabilizing, and hard flutter oscillations (both periodic and quasiperiodic) of the buckled panel are obtained. Furthermore, chaotic motions of an uncompressed panel, as well as a buckled-chaotic transition, and chaos via period-doubling are possible, and the associated Lyapunov exponents are computed. A coexistence of the buckled state with flutter motion may also occur. Results indicate that edge restraints parallel to the flow do not significantly affect the immediate post-critical response, and that a higher-order shear deformation theory is required for a moderately thick/flexible-in-transverse-shear composite panel.