Research On Axial Compression Of Different Strength-Concrete Filled Double Steel Tube Short Columns

In this paper,a new frame system is proposed,in which the different strength-concrete filled double steel tube short(CFDST)column is used as the frame column and the frame beam used the girder with rectangular steel tube and H-shaped opening composite girder connection is achieved through integral nodes,the system can be applied to newly buildings and existed buildings.In order to obtain the axial compression performance of CFDST columns,19 specimens been designed,based on the simplified bilinear model of steel and the nonlinear constitutive model of concrete which considering the hoop effect.Software ABAQUS finite element numerical simulations on eight such axially compressed short columns to obtain load-displacement curves and failure modes.The comparison with existed experimental data verified the rationality beyond the finite element modeling in this paper;Furthermore,the extended parameters of 19 CFDST short columns were analyzed,and the failure mechanism,stress distribution and deformation of these components were given.Finally,the expression of the bearing capacity of the short column which consider the hoop effect is statistically regressed,these lay the foundation for the further study of the seismic performance on the frame system composed of such combined columns.Based on the finite element software ABAQUS,and the finite element models of the CFDST composite column were established,verification and the parameter analysis were carried out,the concrete work of this article is as follows:1,Based on ABAQUS finite element software,the finite element model of the CFDST column was established.The simulation and verification analysis under multiple constitutive structures was carried out.The load-displacement curves under different constitutions were obtained,comparing with the corresponding test results.The rational of finite element modeling was tested;2.Based on the reasonable constitution model,the extend parameters of the CFDST columns were obtain,comparing the load-displacement curves,for which is the influence of different parameters on the ultimate bearing capacity of CFDST columns was studied.The failure mechanism,distribution law and deformation form of CFDST columns were studied.3.Based on the analysis of extended parameters,the formula for calculating the ultimate bearing capacity of CFDST short column been obtained,base on statistically analysis,which laid the foundation for the study of the seismic performance of CFDSTcolumns.