Exact eigensolutions for flutter of two-dimensional symmetric cross-ply composite laminates at high supersonic speeds

Exact eigensolutions for flutter of two-dimensional (2D) symmetric cross-ply composite laminated panel with all combinations of simply supported (S), guided (G), clamped (C) and free (F) boundaries are derived according to classical laminate theory (CLT) and first-order piston theory. The flutter mechanism is revealed with the benefit of eigenvalue properties from both mathematical and physical senses. It is concluded that the coupled-mode flutter, zero-frequency single-mode flutter and buckling can be observed in 2D composite panel. The effects of aerodynamic damping, chord-thickness ratio, in-plane loads, boundary conditions and orthotropic modulus ratio on flutter properties are examined, and in-plane loads and boundary conditions are stressed since they affects both flutter boundary and type. The exact solutions are compared with the results of Galerkin method and the comparison results show that the Galerkin method using the first three modes gives accurate flutter solutions.