Research On Dynamic Performance Of Composite Stiffened Structure With Damping Film Embedded

Composite Structure with Damping Film Embedded(CSDFE)has a wide range of applications in many fields such as aircraft,satellites and precision instruments due to its excellent overall performance.Because of the complexity of the structure,the current research on its dynamic performance mainly focuses on experimental research and simulation,while theoretical research mainly focuses on the simply supported boundary conditions.Theoretical analysis under fixed boundary conditions is currently relatively scarce.In this paper,starting from the fixed-supported boundary condition of the embedded damping membrane composite material,the theoretical study of the plate,beam,and stiffened plate structure is carried out,and the dynamic performance of the embedded damping membrane composite material structure with different parameters is explored in detail.The main innovations of this article are as follows:(1)Combining the piecewise displacement model with Hamilton's principle,the vibration control equation of the composite plate with a damping film embedded under the four-sided fixed-support boundary condition is derived,and a set of modal basis functions satisfying the fixed-support conditions are presented.A theoretical solution satisfying the fixed-support conditions is solved by using Galerkin's weighted residual value,and the theoretical calculation results are compared with numerical simulations.The influence of geometric parameters on the free vibration characteristics of this structure is explored furture.(2)In this paper,a theoretical model of the stiffened beams embedded in damping film composites is presented,and the total strain energy and kinetic energy of the structure are derived by energy average method.The theoretical solution that satisfies the displacement boundary conditions is obtained on the basis of the Fourier triangle series method.The influence of geometeric parameters on the dynamic performance of stiffened beams with embedded damping film is explored on the basis of verification model.(3)In view of the structural characteristics of the stiffened plate embedded in the damping film composite,the vibration differential equation of the structure of the foursided fixed-supported stiffened plate embedded in the damping film composite is established by combinatio of the stiffened beam theroy with the fixed-supported plate theroy.The nature frequency and loss factor of structure are solved by Galerkin method.By the comparison of theoretical solution,numerical simulation solution and modal experiment,the validity of theoretical model is proved.The effect of structural geometeric parameters on the vibration characteristics of stiffened plates with damping film embedded is studied.(4)The experimental platform of the fixed-supported stiffened plate is built,the validity of the finite element model and the theoretical analysis model of the embedded damping film composite stiffened plate are verified by modal experiments,and the free vibration frequency and modal damping of stiffened plate are obtained.Conclusion lays a foundation for the wide application of embedded damping film composite structure.