Experimental Research Of High Strength And Cold-Formed Rectangular Concrete-Filled Steel Tubular Columns Subjected To Eccentric Loading

It’s known to all that application of concrete-filled steel tube is more and more popular for its special character of high bearing capacity,good ductility,economical,refractory.The use of high strength and cold-formed steel for concrete-filled steel tubular members can replace the general Q235 hot rolled steel,which is the requirements of development of new materials and new technology and can improve and perfect this engineering area.The application of high strength steel tube can elevate the tensile strength of concrete filled steel tube,and can be used to promote both concrete and high strength and cold-formed steel.In the process of cold bending steel pipe,only one side need to be welded so that welding quality is easy to achieve and ensure that the performance of the steel pipe is more in line with the requirements.The workload of cold-formed steel tube is less than that of ordinary hot-rolled steel pipe,which can greatly save manpower,and shorten the construction period.And the decrease of residual stress and residual deformation provide a guarantee for the structure’s normal long-term use.At present,there is no report on the study of the performance of the high strength cold-formed concrete-filled steel tube at home and abroad,and the research area is still blank,so this paper has some significance for the research of the high strength cold-formed concrete-filled steel tube.Concrete-filled steel tubular column,as load-bearing components,is mainly used to bear eccentric pressure in practical engineering.This paper focuses on the eccentric behavior of high strength cold-formed concrete-filled steel tubular columns.In accordance with the requirements,a set of test components was designed and processed,and the eccentric experiment was tested.During the whole experiment,the slenderness ratio,width thickness ratio and eccentricity ratio was taken into consideration to study how three parameters influence the eccentric behavior of high strength cold-formed concrete-filled steel tubular columns.Following work in this paper was completed :(1)Q420 high strength cold-formed steel was used to design high-strength cold-formed concrete-filled steel tubular column,and test program was established according to the test method and test conditions.During the eccentric compression static load test,the failure mode,bearing capacity,mid-span deflection,relationship of vertical and lateral force under the eccentric stress and vertical displacement was studied.(2)Parameter analysis of high strength concrete-filled steel tubular columns was completed on the basis of the influence of design.The slenderness ratio,width thickness ratio and eccentricity ratio was set as mainly factors to analyze the impact on such construct component(3)ABAQUS was applied to simulate the whole eccentric failure process of high strength concrete-filled steel tubular columns.To begin with,the relevant parameter was repeatedly regulated and the suitable constitutive model of steel and concrete materials was chosen.And then,reasonable unit type was sought,and the contact and constraints was correctly defied,and the boundary conditions was exactly set,and the mesh was accurately divided,and the finite element model was establish for comparison.At last,the correlation curves was obtained to compare with the test results data.(4)According to the test results and the finite element simulation,the calculation formula of the correlation curve for the high strength and cold-formed concrete filled steel tube eccentric members was presented.