| Embedded and Co-curing Damping Composite(ECDC),as a new high-damping and high-stiffness composite material,has a wide applications prospect in super-high-speed aircraft,rockets and other fields.At present,the hotspot is limited to ECDC plate and beam structures.There is little research on the dynamic characteristics of ECDC stiffened shells.Therefore,on the basis of previous researcher work,study it from three aspects: experiment,numerical simulation and theoretical analysis.The main work and innovation are as follows:(1)On the basis of the secondary bonding method,the manufacturing process of the stiffened structure is divided into three steps: First,it is proposed to use a mold to fabricate a pair of "L" shaped ribs at a time,and the T-shaped rib is further made.Then,the ECDC panel is made by double-sided brushing and the co-curing process.Finally,the ECDC stiffened structure were manufactured by bonding them together.(2)The modal test is carried out on ECDC,undamped composite materials plates and their stiffened structure,respectively,and the dynamic performances among different types of structures are obtained.On this basis,the finite element model is established.The results obtained by the two methods are compared with each other to verify the validity.(3)Based on the first order shear deformation theory and taking the ring stiffeners as discrete elements,the governing vibrational equations of ECDC open cylindrical shells with ring stiffener are derived by using Rayleigh-Ritz method and Navier solution function.The results are compared with those obtained by finite element method to verify validity of the theoretical model.(4)On the basis of the foregoing research,the finite element model of ECDC open cylindrical shell with T-shaped stiffeners is established,and the dynamic behavior of the structure with different stiffener size,stiffener position and damping layer parameters is studied respectively,which provides a reference for the further research of ECDC stiffened shell. |
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