| As a new type of composite structure, the concrete filled steel tubular column and the concrete-filled double skin steel tubular column have been widely studied and applied. And FRP-concrete-steel double-skin tubular column(FRP-concrete-steel double-skin tubular column, referred to as DSTC) is different from the above two structures, and also different in FRP concrete filled steel tube, it is a new type of composite structure, the structure by FRP cloth(carbon fiber reinforced resin) material tube, steel tube and filled in between the two concrete composition, three kinds of materials of collaborative work make the portfolio structure is much better than existing components in mechanical properties. The FRP cloth has higher quality strength ratio, corrosion resistance and good fire resistance, light weight and other advantages, so FRP-concrete-steel double-skin tubular column can as load-bearing components used in the subway, the stadium, the offshore platform support columns, piers and other structures. Lateral impact load is a kind of unexpected load which is inevitable in the normal work of the above structure, and the knock-on effect could lead to structural damage and even loss of bearing capacity when the structure is in use process accident suffered to lateral impact accidents such as vehicles, ships, poses a serious threat to people’s life and property safety extremely easily, so must be fully considered in the structural design.At present, the research on DSTC is mainly focused on the static performance, such as the axial compression performance. However, the research on the impact resistance of DSTC has not been reported.In this paper, the application of the new structure of DSTC on the bearing column is studied, and the impact resistance of FRP-concrete-steel double-skin tubular column is analyzed through the test and theoretical study of the lateral impact. The main research contents of this paper are as follows:1、The FRP-concrete-steel double-skin tubular column under lateral impact test was carried out on the drop hammer impact test machine(DHR9401) of Taiyuan University of Technology, the parameters of the test include the impact height and the number of FRP layers on the surface of the specimen. Through the test instrument to capture the impact force(F)of the specimens, midspan deflection(Δ) and FRP surface 1/4 across to the right of the strain(??)test data at the same time, also get the whole residual deformation and local failure form of the specimens and the impact test results analyzed and demonstrated.2、In key consideration under the premise of anisotropic materials and FRP strain rate, using ABAQUS finite element software to establish performance analysis model of FRP-concrete-steel double-skin tubular column of both ends fixed under lateral impact.Through the material tensile test determined the steel material, the FRP parameters, and in accordance with the actual situation defines the contact properties of the components and the like.Also under the premise of the test has limitations, in order to analysis more real impact event condition, to ensure that before the impact has been pre-applied axial force on the specimen, so before the impact model based and the establishment of a axial force- the impact of coupling model.3、By comparing with the experimental results, the validity and effectiveness of the material constitutive model, the contact property and the boundary condition of the model are verified.On the basis of the finite element model is proved correct, then analysis the different hollow rate(χ), different load parameters of impact energy(E0) and axial compression ratio(n) on the dynamic performance of FRP-concrete-steel double-skin tubular column test under lateral impact. at the same time, it also analyzes the reasons for the impact and puts forward some related suggestions. |
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