FINITE-ELEMENT NONLINEAR FLUTTER AND FATIGUE LIFE OF 2-DIMENSIONAL PANELS WITH TEMPERATURE EFFECTS

A frequency domain method for two-dimensional nonlinear panel flutter with thermal effects obtained from a consistent finite element formula tion is presented. von-Karman nonlinear strain-displacement relation i s used to account for large deflections, and the quasisteady first-ord er piston theory is employed for aerodynamic loading. The panel motion under a combined thermal-aerodynamic loading can be mathematically se parated into two parts and then solved in sequence: 1) thermal-aerodyn amic static deflection (time-independent equilibrium position), and 2) limit-cycle oscillations. The finite element frequency domain results are compared with numerical time domain solutions. In a limit-cycle m otion, the panel frequency and stress can be determined, thus fatigue life can be predicted. The influence of temperature and dynamic pressu re on panel fatigue life is presented. Endurance and failure dynamic p ressures can be established at a given temperature from the present me thod.