Supersonic Panel Flutter Analysis Assuming Effects of Initial Structural Stresses

Abstract

The work is devoted to studying the stability of an elastic plate in a supersonic gas flow. This problem arises in the study of the phenomenon of panel flutter, buckling and vibration intensity of airplane and missile thin-walled structures, excited by their interaction with the airflow at high-speed flight. It is important to avoid the panel flutter occurrence to increase the structure lifetime. The vibrations of a rectangular isotropic thin plate in a supersonic airflow are studied to find the flutter speed and analyze it. Using Bubnov–Galerkin method and aerodynamic model by piston theory in supersonic fluid dynamics, effects of longitudinal and lateral stresses on the divergence speed and flutter characteristics of the panel have been analyzed by MATLAB coding. To this end, by finding the panel vibration natural frequencies and drawing the vibration graphs, flutter speed has been determined and stress effects on this speed have been discussed. The numerical results show that initial in-plane stresses have a significant effect on flutter speed of the plate. Compressive longitudinal stress will increase the panel dynamical instability, and stretching stress in this direction will decrease it. Furthermore, compressive stresses in lateral (perpendicular to the flow) direction will decrease the panel dynamical stability, and stretching stress in this direction will increase it. Using this information, the most dynamic stable and unstable zones in airplane structures can be determined.