Supersonic nonlinear panel flutter suppression using shape memory alloys

An efficient finite element procedure is developed to predict large-amplitude nonlinear flutter response of shape memory alloy hybrid composite plates at an arbitrary supersonic yawed angle and an elevated temperature. The temperature-dependent material properties of shape memory alloy and traditional composites, as well as the von Karman large deflections, are considered in the formulation. Finite element system equations of motion are transferred to aeroelastic modal coordinates to reduce the large number of structural-node degrees of freedom. Time-domain numerical integration is employed to analyze flutter behaviors of the shape memory alloy hybrid composite panel under thermal loads. The flutter stability regions under the combined aerodynamic and thermal loads are studied. All of the possible behaviors, including the two types of static behavior and four types of dynamic motion of flutter, can be predicted for shape memory alloy hybrid composite plates. The static behaviors are 1) flat and stable and 2) aerothermally buckled but dynamically stable. The four types of dynamic motion are nearly simple harmonic limit-cycle oscillation, periodic limit-cycle oscillation, quasi-periodic oscillation, and chaotic oscillation. The flutter response of shape memory alloy hybrid composite plates are compared with those of traditional composite plates without a shape memory alloy. Results show that the desired flat and stable region can be greatly enlarged by using a shape memory alloy.