Study On Performance Of Circular Concrete-filled Steel Tubular(CFST) Columns Under Velocity Transverse Impact

Concrete-filled steel Tube makes use of the restrain between steel and concrete,and the concrete is under triaxial stress states.Interaction of concrete and steel tube can immensely improve bearing capacity and plasticity of Concrete Filled Steel Tube.As Concrete Filled Steel Tube can fully reflect the advantage of concrete and steel,and have a series advantages like construction convenience,saving space and excellent anti-seismic property,Concrete Filled Steel Tube is widely used in high-rise buildings,large-scale bridge,industrial factory buildings,subsurface structure and so on in recent years.In the using procedure,the concrete-filled steel columns not only should bear static,but also the effect of impact force and blast load.At present,the scholars have made a lot of theoretical analysis and experimental research on concrete-filled steel columns.However,there are few research on performance of circular concrete-filled steel tubular(CFST)columns under velocity transverse impact,therefore,it is necessary to study performance of circular concrete-filled steel tubular(CFST)columns under velocity transverse impact.Performance of circular concrete-filled steel tubular(CFST)columns under velocity transverse impact is studied in the paper,The main contents include the following points:(1)Impact experiment: On the gravity drop weight test machine,do the side knock experiments of 16 columns.Among them,14 are single impact,and the 2 are continuous impact.By changing the impact height,the diameter of the member and the thickness of the steel tube,The failure modes of the component,the time history curve of the impact force,the mid-span deformation and the surface strain curve of the steel pipe are obtained?(2)Experimental phenomena and data analysis: Through the failure modes of the component,the analysis of the impact force time history curve,the mid-span deformation and the strain curve of the steel pipe surface,find the concrete-filled steel tubular column has good plasticity and impact resistance and the influence of the impact height,the diameter of the specimen and the wall thickness of the steel tube on the dynamic response of the concrete filled steel tubular columns.(3)Numerical simulation of impact test: Build fine model of CFST columns under velocity transverse impact,compare with the test results.Simulation results show that: the calculated results are in good agreement with the experimental results and the established finite element model can effectively simulate the mechanical behavior of concrete filled steel tubular columns under lateral impact loading.