Study On Concrete-Filled Square Tubular Column To Steel Beam Connection With Internal Diaphragm

As one of new composite structures in the field of Civil Engineering,concrete一filled rectangular steel tubular(CFRT) structure has high capacity,large energy absorption capacity,and high ductility,also it has regular shape which is easy to connect between columns and beams,convenient fire-control measure and short construction time. Therefore CFRT structure will become popular in medium-high rise residential construction. As one vital area, joint of beams and column is in complex stress condition and its types are varied. For the moment, there is not a set of rounded theory of calculation and design method yet. Thus investigation on joints between CFRT columns and steel beams in medium-high rise residential construction has significant theoretical and applied value.Based on the achievements in theoretical research, the nonlinear FEM model involving geometric large deformation, materials nonlinear is presented. The Von.Mises failure criterion and bilinear kinematical hardening stress-strain relationships have been used for steel and the elastic-plastic stress-strain relationships used for concrete. The concrete cracking is used for the discriminating criteria in terms of ANSYS. The 3D models of beam-to-column connections by 3D solid elements are founded. And the capacity behavior of connections with internal diaphragms under the monotonic loading and cyclic loading are analyzed. The results of nonlinear FEM analyses can show the stresses distribution in the joint better, so that it provides the possibility to patch up the defects that couldn't observe in experiments in the details. And then, various factors of the influences of joints capacity behavior can be analyzed such as changing thickness of steel column s and internal diaphragms,concrete strength, and reinforced concrete slab etc.Study the damage mechanisms and design principles of the joints of beams and column. Introduce the mathematical formulas for determining joint shearing capacity and bending capacity(CECS159:2004)in Chinese Design Code.According to the results of this paper, this thesis presents the construction details and it can be provide the reference to the engineering design.