Sesmic Beahvior Of Prefabricated Reinforced Concrete Column-Steel Beam Connections

In the structural design,steel beam can be used to reduce the amount of templates as well as the size of components,while the use of reinforced concrete column can improve the lateral stiffness of structures and reduce the requirements of structural corrosion and fire prevention,indicating higher economical benefits.A new type of connection,combining prefabricated reinforced concrete column and steel beam,is proposed in this research.It has the advantages of prefabricated reinforced concrete column and composite structure.Furthermore,through reasonable design on embedded bar and T-stub,the failure mechanism of the connection can transform the plastic hinge to the T-stub.Therefore,the beam and the column can be protected and quick repaired,and the replacement of damaged components can be easily conducted.The mechanical properties and working mechanism of this proposed connections were studied under static and cyclic loading by means of both experimental tests and finite element analysis in this paper.The influence of different structural parameters on mechanical properties of connections was analyzed,and the bearing capacity of the connection under static and cyclic loading was examined to understand the damage law of connections under different loads.The main research contents are as follows:(1)The experimental results of two prefabricated reinforced concrete column-steel beam connections under static loading were presented.The effects of the embedded bar and the addition of web angle on bearing capacity and failure mode of connections were studied.Accordingly,the static bending resistance of the connection was evaluated,which will provide experimental data and basis for the finite element analysis.(2)Four prefabricated reinforced concrete column-steel beam connections were designed and tested under low reversed cyclic loading.The effects of the thickness of T-stub flange,the strength of embedded bar,and the addition of web angle on the seismic behavior of connections were examined.Tests mainly examined the seismic response of the connection,including the failure mode and the moment(M)-relative rotation(?)curves.Then,the force transfer mechanisms,the bearing capacity,strength degradation,stiffness degradation,ductility and energy dissipation of connections were investigated based on the failure mode and moment(M)-relative rotation(?)curves.(3)A finite element model was developed to simulate the flexural behaviour of T-stub connections with prefabricated reinforced concrete column and steel beam by using ABAQUS software.The calculated results were verified by experimental results,and the effects of the diameter of embedded bar,the strength of embedded bar,the thickness of T-stub flange and the addition of web angle on the mechanical performance of connections were studied by the developed FEA models.Meanwhile,the failure mode and force transfer mechanisms of connections were analyzed by finite element analysis.Moreover,the nonlinear full-range analysis of these connections were executed by using the analytical models.The ultimate bearing capacity of these connections were then decided by moment(M)-relative rotation(?)curves.Importantly,the difference between load-displacement skeleton curve of low reversed cyclic loading and load-displacement of static loading was clarified.Finally,the stress development law of connections was also studied by analyzing the stress distribution of connection key parts.