Dynamic characteristics of carbon fiber reinforced and fixed supported composite beams with co-cured multilayered viscoelastic films

To improve the damping performance of carbon fiber composite beams with co-cured multilayered viscoelastic damping films, the free vibration characteristics and structural optimization of the composite beams were explored. In this article, a mathematical model of the structure is established based on the first-order shear deformation theory. The strain energy, kinetic energy and dynamic differential control equations of the carbon fiber composite beams with co-cured multilayered viscoelastic damping films are derived by using variational principle and Hamilton principle to explore the displacement function satisfying the boundary conditions of fixed supports at both ends. Galerkin method is proposed to solve the theoretical solution of free vibration of beam structure under fixed support boundary condition. The correctness of the theoretical model is verified by fabricating multilayered damping sandwich composite beam specimens and building an experimental platform for modal experiments. The effects of film distribution and geometrical parameters on the dynamic performance of co-cured damping composite beams were investigated. Finally, it is found that when the structure of carbon fiber composite beams with co-cured multilayered viscoelastic damping films is symmetrical, its dynamic performance achieves the optimal. This work provides a theoretical basis for optimal configuration of multilayer damping film embedded in composite structures.