Influence of concentrated elastic support on flutter characteristic of curved panels

A method for increasing the flutter dynamic pressure of curved panels with a concentrated elastic support was proposed and the effects of the concentrated elastic support position and its stiffness on the flutter velocity of curved panels were studied. The nonlinear aeroelastic model of a curved panel with a concentrated elastic support in supersonic air flow was established using the virtual work principle and the finite element method. The large deformation of the curved panel was described by using Von Karman large deformation strain-displacement relationship. The quasi-steady first order piston theory was used to calculate the aerodynamic force acting on the surface of the curved panel. The eigenvalue solution was then utilized to determine the flutter dynamic pressure of the curved panel. The dynamic characteristics of the curved panel were analyzed by changing the stiffness and position of the concentrated elastic support based on the frequency coalescence theory. Results showed that the elastic support located in different positions has significantly different effects on the flutter dynamic pressure; the elastic support located in the central region of the curved panel or in the chordwise middle line leads to a drop of the flutter dynamic pressure, and the flutter dynamic pressure decreases with increase in elastic support stiffness; if the elastic support is located in the center of the curved panel, the flutter dynamic pressure has a maximum drop; when the elastic support position changes along the line perpendicular to the flow stream and is far away from the chordwise middle line, there is an increasing of the flutter dynamic pressure, and the flutter dynamic pressure increases with increase in elastic support stiffness; while the elastic support position changes in the area near leading edge and trailing edge and along the flow stream, the flutter dynamic pressure increase; the method of adding a concentrated elastic support to increase flutter dynamic pressure can be applied as a measure to control the flutter of a curved panel, and the elastic support should be located on the spanwise midline with a distance of 20% chord length from the boundary.