Structural stability of functionally graded panels subjected to aero-thermal loads

Static and dynamic stabilities of functionally graded (FG) panels which are subjected to combined thermal and aerodynamic loads are investigated. The volume fractions of constituent materials composing the FG panels are assumed to be given by a simple power law distribution. Material properties of the FG panels are obtained by a linear rule of mixture. Panels are considered as rectangular plates which are based on the first-order shear deformation theory. The von Karman strain–displacement relation is used to account for geometric nonlinearity, which is caused by a large deformation. The first-order piston theory is used to simulate supersonic aerodynamic loads acting on the panels. Equations of motion are derived by the principle of virtual work and numerical solutions are obtained by a finite element method. The Newton–Raphson method is applied to get solutions of the nonlinear governing equations. Flutter boundaries are defined by linear flutter analysis and the Guyan reduction is applied to reduce degree of freedom for eigenvalue analysis. The influence of the material constitution, asymmetric characteristics of FG panels on thermal buckling and flutter characteristics are examined. Static and dynamic stability margins of FG panels are defined for various volume fractions.