Research On Concrete-filled Circular Steel Tube Column With Force Transmission Members

With the rapid development of construction techniques, high-rise buildingsand super high-rise buildings has become an inevitable trend of modernarchitecture, the core concrete of concrete-filled steel tube (CFST) has increasedcompressive strength due to the confining effect offered by the steel tube, whichhas the advantages of high bearing capacity, good ductility, so it is widely usedin high-rise and super high-rise structures, but in the actual engineering workingtogether of the concrete filled steel tube can not be guaranteed. Therefore thereare insecurity problems.So far, at home and abroad the practical application of CFST by the externalload, the load are acted on the steel tube first, and then through the interfacebonding between the steel tube and the concrete transfer to core concrete. Theexisting axial compression experiment on the CFST showed that, when the loadon the steel pipe, the working together of CFST can not be guaranteed. But thecurrent numerical and experimental studies generally assume that the steel andconcrete is completely work together, and the loads are directly loaded on the topof the column, which is not realistic.In view of the working together problems, Fu Xueyi professor presents areasonable force transfer mechanism, namely the force transmissionmembers-distribution beams and inner ring ribs, in order to coordinate thedeformation between steel tube and core concrete, and enhance the ability ofworking together, to improve the performance of CFST. This paper has carriedout research on the mechanical behavior of CFST members subjected to axialcompression， which setting vertical ribs, studs, inner ring ribs, distributionbeams, distribution and inner ring ribs.The mechanical behavior of CFST with distribution and inner ring ribs areanalyzed under axial compression, bending, combined compression and bending.Influences of strength of steel, strength of concrete, and steel ratio on bendingcapacity of CFST were investigated systemically, and influences of strength ofsteel, strength of concrete, steel ratio and axial compression ratios oncompression and bending bearing capacity.