Aeroelastic Flutter Analysis And Control Of Composite Panels

Panel flutter is a typical aeroelastic phenomenon occurring on high-speed aircraft.When the flutter occurs,the lateral vibration amplitude of the panel will increase sharply,which seriously threatens the safety of the aircraft.With the continuous development of modern science,laminated structures with light weight and high specific strength are gradually applied to the design of aircraft structures,which makes the corresponding aeroelastic flutter problem more prominent.In order to enhance the aeroelastic stability of the panel structure,based on the nonlinear piston theory,Von-Karman large deformation displacement-strain relationship and Galerkin discrete method,the aeroelastic flutter model of composite laminated panel is established and the flutter control research is carried out.The main contents are as follows:The third-order nonlinear piston theory is used to represent the aerodynamic force,and the nonlinear partial differential equations of motion of composite panels are derived by combining the Von-Karman nonlinear strain-displacement relationship and Hamilton principle.The Galerkin discrete method is used to convert the partial differential equations of system motion into ordinary differential equations.The dynamic response of the composite panel is numerically simulated to obtain the critical flutter dynamic pressure of the system.The effects of the aspect ratio,ply angle and boundary conditions on the flutter behavior of the composite panel are studied.Shape memory alloy(SMA)fiber was used to control the flutter of composite panels.Von Karman large deformation theory is used to describe the nonlinear relationship between displacement and strain of the panel,and the third-order nonlinear piston theory is used to express the aerodynamic force.The restoring force of SMA fiber in the confined state is simulated according to the one-dimensional Brinson model.Combined with Hamilton principle,the nonlinear partial differential equations of SMA composite panel are derived,and the ordinary differential equations of motion of the system are obtained through Galerkin method.The critical flutter dynamic pressures of traditional composite panels and SMA composite panels are compared,and the effects of SMA fiber laying angle,volume fraction,prestrain and temperature on the critical flutter dynamic pressures and limit cycle amplitudes of composite panels are analyzed in detail.The flutter control of composite panels was carried out by installing stiffeners.The stiffened panel is equivalent to the stiffening subsystem and the composite panel subsystem.The differential equation of the stiffening subsystem is established according to the Euler Bernoulli beam theory.The aeroelastic flutter model of the composite stiffened panel is derived by combining the differential equation of the composite panel established previously.The effects of stiffener height,width and location on the critical flutter dynamic pressure and limit cycle amplitude of composite panels are studied.