Study On Mechanical Properties Of Three-leg Steel Tube Box Section Column Under Axial Compression

Steel structure has been widely used in the field of building and bridges for its advantages of uniform material,high strength,good welding performance,good seismic performance,easy processing,industrialized production,fast installation and construction,and reusable steel.In the common steel structure members,the box section has become the common section form in the bridge,beam,workshop and other structures because of its large rigidity in the transverse and longitudinal direction of the section.With the progress of the times,the simple steel box section cannot meet the diverse needs of the society.In order to further improve the bearing capacity of the box section members,some scholars proposed to fill the concrete in the box section,some scholars are studying the use of high-strength steel box section members.This paper studies the steel tube box section column,that is,the combination of steel tube and box section to improve the bearing capacity of box section members.In this paper,the mechanical properties of three leg steel tubular box section columns under axial compression are studied by the method of experiment and finite element.The main research of this paper is as follows:(1)The mechanical properties of two steel tubular box section columns and one concrete-filled steel tubular box section column under axial compression were studied.The load longitudinal and transverse strain curves,the load longitudinal strain curves and the load axial displacement curves of the web section are obtained.(2)The test results of three box section columns are systematically analyzed,and the longitudinal and transverse strain variation laws of the steel tube mid-span section,the longitudinal strain variation laws of the web section and the axial displacement variation laws with the load are studied.(3)The finite element model of steel tube box section column is established by using ABAQUS large-scale finite element analysis software,and the correctness of the finite element model is verified;the results of finite element analysis are compared with the deformation form and load axial displacement curve obtained from the test.(4)Based on the ABAQUS finite element model,the influence of the ratio of diameter to thickness of steel tube,the ratio of width to thickness of web,the strength grade of steel and the strength grade of concrete on the ultimate bearing capacity of three-leg steel tube box section column is studied.