Study Of Y-shape Concrete Filled Steel Tube Transfer Joint’s Design

High-rise buildings and skyscrapers are developing rapidly in nowadays. Considering the diversification of the function, the bottom of the high-rise office buildings or apartments are usually used as large malls, hotel lobbies or other large span space. So reasonable structure layout, in which upper column layout is relatively sparse with lower stiffness, and it gradually becomes dense with higher stiffness when it goes down can not satisfy people’s needs. To realize this kind of structure layout, transfer story became widely used in engineering. With the advantages of transmitting force directly, higher bearing capacity, smaller section, better service space, significant economy benefit and so on, the inclined column-shaped transfer structures with concrete-filled steel tubular(CFST) members have wide application prospect.This paper is to explore a new design for the inclined column-shaped transfer structures with concrete-filled steel tubular, based on the study of CFST joints and CFST column-steel beam joints. First of all, a new constructional measure of the joint transferred from two inclined square CFST columns to a circular supporting CFST column was proposed. Then 8 specimens with different parameters were designed and conducted to vertical compressive experiments to analyse it’s bearing capacity, strain distribution and deformation ability. Then ABAQUS finite element analysis are used to verify the validity of the process of finite element model and to make further analysis of the depth of inclined columns’ influence on the bearing capacity and the failure mode of the Y shaped joint structure. Finally, according to the results of the experiments and the finite element analysis, a new kind of form named vertical welding ribbed plate transfer joint structure with concrete-filled steel tubular is proposed as the optimized structure. The new transfer node is convenient for construction, which has many advantages such as transmissing force directly, bearing relatively high strength, small member section etc. The results of this study can provide significant academic value for perfecting the theoretical research system, about the mechanical behavior of the joint of CFST structure under complex load conditions. Meanwhile, it also provides theoretical basis and design reference for engineering.