Simulation Study Of CFST Short Column Subjected To Axial Compression Based On The Constitutive Relation Of Concrete

As a kind of composite structure form, Concrete Filled Steel Tube (CFST) can givefull play to the characteristics of the steel and concrete materials, and to a certain extent, tomake up for the defect of the material. Because of the interaction of Steel and concrete,CFST has excellent bearing and deformation performance. Therefore, the application andresearch about CFST is very active in recent years. Previous research shows that, the con-stitutive relation of core concrete and constraining coefficient (expressed as ξ) has sig-nificant effects to the mechanical properties of CFST. Therefore, the study of the coreconcrete constitutive relation has important practical significance.This paper, based on the different core concrete constitutive relationship, aims to es-tablish the finite element model (FEM) of the circular CFST under axial compression. Themain contents were summarized in detail as follows:1. Summarize the basic phenomenon and the results of the test of short column, themechanism of the constraint effect and the existing constitutive relationship of the coreconcrete of CFST. On the base of Liu-Han’s core concrete constitutive relationship, a pre-liminary amendment is suggested.2. Choose typical test results and establish FEM of the circular CFST under axialcompression. Through the comparison between the experimental results and numericalcalculation results, analyzing the numerical model is reasonable or not.3. Based on the analysis of previous results, it can be proved that the preliminaryamendment of Liu-Han’s core concrete constitutive relationship is reliable and the cor-rected constitutive relationship can be used to obtain the Load-deformation curve of simi-lar components.4. Choosing typical codes at home and abroad to design selected components. Ac-cording to the calculation results, According to the calculation results, this paper puts for-ward the design suggestions for reference.