Cfst Column Node Static Model Pilot Study

A new type of column-beam joint of concrete filled steel tubular is presented in this thesis. The character of this joint is that the core steel tube connects the outer steel tube up and down which is discontinuous in the joint Zone. While ring and vertical steel bars are close packed in the joint zone and the longitudinal steel bar of the RC beam can go through the joint zone. The new type of joint makes beam and concrete in the joint zone become one, and moment, shear and axial compression can be carried in a good conditionThrough carrying out the module experiments and finite elements analysis of three middle column-beam joints and two side column-beam joints of CFST, this thesis studies the feasibility and mechanical properties of this new type of joint.1. Carrying out a experiment of axial compression of outer column and core column of CFST before the experiments of joint, the author primarily studies the problem of capacity of CFST in contrast with criterion of all countries. It makes preparation for the choice of formula of calculating the capacity of CFST and joint.2.Carrying out module experiments of joint and getting correlative experimental data , the author studies the feasibility and mechanism of joint through analyzing the experimental data.3.Carrying out nonlinear finite element analysis of specimens using FEA program, the author lays a foundation for the study of the mechanism and the method of design of joint.4.Based on the results of module experiments and finite element analysis, the author makes a preliminary study on the mechanism of joint.For sake of time, this thesis only makes a study on the static mechanical properties. More researches on the seismic properties and mechanism of the joint should be made.