Seismic Behavior Research Of Fabricated T-shaped Steel Tubular Column Joints Under Horizontal Load Of Flange

The rise of special-shaped column structure benefits from the better promotion of its residential area and usage function.After the system was put forward,it has been implemented and widely used in all parts of the country.However,the weakness of nodes restricts the implementation of this structure.In this paper,a prefabricated special-shaped column structure is proposed by the seismic test group of North China University of Science and Technology.The joints of the structure are the decisive bearing parts,in order to fully study the mechanical characteristics of the joints,the horizontal reciprocating loading test in the flange direction was carried out for the assembled Tshaped concrete filled steel tubular column joints.By analyzing the data obtained from the experiment,the following main research results are obtained:1)Through the full-scale model test,the performance of the joint model under different axial compression ratio is explored when the flange is loaded horizontally.The results show that the assembled T-shaped concrete-filled steel tubular columns eventually form the form of bending shear failure.When the axial compression ratio is 0.3 and 0.4,the bearing capacity is increase by 3.3% and 15.9% respectively,the ductility coefficient is within 2.5?3.5,the viscous damping coefficient is between 0.1?0.2,the ultimate displacement angle is more than 1/50 and there is no collapse.The displacement at the joint of the horizontal joints of the specimens is less than 0.6mm,which shows that the assembled T-shaped concrete-filled steel tubular columns have no collapse.Each data of the concrete column has obvious advantages over the ordinary special-shaped column.2)Based on the test,the stress state of the joint is analyzed,and the calculation formulas of the shear and crack resistance capacity of the joint are derived.The calculation results of the formulas are in good agreement with the test results.The restoring force model of assembled T-shaped concrete-filled steel tubular column is put forward.Based on the data obtained from the test and through linear regression analysis,the skeleton model and calculation formula of each stage are established,and the rigidity degradation rule and calculation formula of the test piece are fitted.The hysteresis model of assembled T-shaped concrete-filled steel tubular column is established by combining the skeleton model with rigidity degradation rule.Figure 45;Table 15;Reference 71...