Analytical Behavior Of Dendriform Connections To Concrete Filled Steel Rectangular Tubes

The bifurcate column together with double-cruciform connections of column to beam form the dendriform connection to concrete filled steel rectangular tubes. Firstly experimental studies on four groups with six 1/2-proportional Specimens are done in this paper. The strain of steel tubes and beam under the static and low-cycle repeated load are accurately measured, and then their curves are obtained. Meanwhile, 3D nonlinear Finite Element Model which all nonlinear effects of material, geometry and contact interface are considered are established. Systematic studies of dendriform connection to concrete filled steel rectangular tubes are done.The comparison of the test data and finite element analysis results show that the FEA results is good agreement with the test data, and verify the correctness of finite element model, Note that the analysis of such complexity connections is feasible with ANSYS. From the load-displacement curve at the end of beam and hysteretic curves which are obtained by experiment and finite element analysis, the aseismic behavior of the dendriform connections are studied.According to the results of finite element analysis, the contours of stress distribution of the steel tubes, the core concrete and the inside clapboards are given in this paper. The structural deformation shapes and weak regional under the load effect can be clearly observed in these figures, and a limitation that the distribution of stress inside of the steel tubes can not be observed during experiment is supplied. The force transmission track, bearing mechanism behavior and failure mode of the dendriform connection are investigated. The analysis shows that when the overall structure is under normal working loads, this dendriform connection is in a flexible state, which is according with requirements. Accordingly, the style of connection is more abundance. The influence on Performance mechanical of the dendriform connection with variation of the axial compressive ratio and the steel tube's thickness are considered by adjusting finite element model.This thesis puts forward some guarding measures to the limitation of such dendriform connections, in order to provide references for research and designers.