A method to calculate the flutter critical value of a cantilever plate wing subjected to aerodynamic heating is presented. When the temperature distribution of a wing is given, thermal stresses are analyzed by the principle of minimum complementary energy, and the critical value is calculated by the direct method of the variational problem. Some examples obtained by the present method are illustrated. The influence of a loss of bending stiffness on the critical value of a rectangular wing is clarified quantitatively. Furthermore, the influence of a wing planform, i.e. the sweep-back angle and the taper ratio, on the flutter characteristics of low aspect ratio trapezoid wings is shown.
The flutter tests of cantilever wings in a heated wind tunnel at Mach number of 4.75 and the comparison with calculated results are presented. Test pieces are stainless steel trapezoid flat plates. Flutter was observed in a certain time duration when the temperature difference was higher than the critical one at a thermally transient state. Temperature distribution of a wing surface was measured by thermocouples. Using this distribution, the critical value is calculated by the authors' method. Good agreement is seen between theory and experiment.