Study On Behavior Of Concrete-Filled Steel Tubular Columns Under Local Compression

Local compression is very popular in practical engineering, such as bearing of supporting columns, joint of prefabricated columns, hinge support of space rigid frames, grid structures and arch structures, etc. The comprehensive tests and theoretical modeling of the behavior of concrete-filled steel tubular (CFST) columns under local compression has been conducted at home and abroad; however, the available studies mainly concentrated on the situation that both bearing plate and CFST column had the same cross-section. Currently, there is no literature about the behavior of CFST columns under local compression when the cross-section of bearing plate and CFST column are different.The behavior and design method of CFST columns under local compression are experimentally and theoretically studied in this paper, and the main contents are as follow:(1) Tests on circular and square CFST columns under local compression were carried out considering the effect of cross-section of bearing plate, local compression area ratio and thickness of endplate, and particularly to investigate the behavior of CFST columns under local compression with bearing plate and CFST column having the same cross-section.(2) A finite element analysis (FEA) model of CFST columns under local compression was developed using ABAQUS, and the predicted failure pattern, load versus deformation curves and bearing capacity generally agreed well with the experimental results.(3) Based on the verified FEA model, the effect of typical parameters on the mechanism of CFST columns under local compression was systematically investigated.(4) The simplified formulae for the bearing capacity of CFST columns under local compression were suggested, and in general the simplified results accorded well with the experimental results.