Simulation Analysis Of The Polygon HCFST Short Column Subjected To Axial Compression

Abstract:CFST (Concrete filled steel tube) is a kind of the composite structure which is made of steel tube filled the concrete in site, and HCFST (Hollow concrete-filled steel tube) is a ideal composite structure by using prefab concrete tube inside or centrifugal molding technology after evaporation. The interaction interaction between two materials of this composite structure made the polygon HCFST much more advantages, for example, local buckling of the steel tube will be delayed because of the concrete filled, at the same time, the strength and plasticity of the core concrete can be improved because of the steel tube. However, at present there are not only a fully mature theory for HCFST, especially for the polygon HCFST, but also rarely related design codes and engineering practices. The main reason is that the mechanical properties of this structure is more complex, so it needs to be studied further This paper, basing on this background and existed research results, will use the finite element method to launch on the in-depth research about the parametric analysis of the polygon HCFST short column subjected to axial compressiom performance, the main contents are as follows:(1) Through theory and finite element method, the author studis the whole process of analysis of the work mechanism, failure pattern and the distribution regularity of stress of the two materials about axial compression analysis of HCFST and summarizes the existing steel and concrete material constitutive relation that is suitable for HCFST simulation calculation.(2) Choose typical test results and establish the finite element analysis of the polygon HCFST under axial compression, record and contrast date that the ultimate bearing capacity and deformation characteristics of from test and FEM, then verify the analysis accuracy of the data calculated under different constitutive relation. Eventually determine the optimal material constitutive model that suitable for the polygon HCFST axial compression short column simulation analysis.(3) In view of the limitation and deficiency of the present research, carry out the simulation analysis of bearing capacity by using general finite element software ABAQUS to create the polygon HCFST model under a single force. Research on the action of the impact on the ultimate bearing capacity from different parameters (the strength of steel tube, the strength of concrete, ratio of hollow, cross section form and two kinds of material interface friction coefficient), And then put forward some design suggestions for reference.(4) Summarize domestic commonly formula of bearing capacity of the polygon HCFST under axial compression, and compare the results and expression form of each relevant formulas, then combining the relevant data of FEM calculation in this paper, fit general simplified formula about the axial compression bearing capacity of the polygon HCFST short column. Finally compare the fitting formula with the test results, and prove the feasibility of its engineering application.