Seismic Behaviour Of The Connection Between Prefabricated Reinforce-Concrete Shear Wall And Concrete-Filled Steel Tube Column

A new type of shear connection is proposed in this paper for the interface of prefabricated RC shear wall and CFST columns,and then experimental research and finite element analysis were carried out for the connection.The main contents of this thesis are as follows:(1)Four 1/5 scale connection specimens,including 3 prefabricated RC shear wall and CFST columns connections,and one reference cast-in-place specimen were tested under cyclic loads to study the effect of distance between shear connectors(150mm-300mm)and strength of post poured concrete(C40-C60)on failure mode and the hysteretic behavior of the connection.The experimental results show that:during the whole test,the failure of the specimens were mainly concentrated on the shear connectors and the concrete near the shear connections,all the specimens were failed due to the failure of the shear connections;the bearing capacity of the specimens increased about 35%when the distance of the shear connectors change from 300mm to 150mm,and the ductility and energy dissipation capacity were also improved;with the increase of the strength of post poured concrete(from C40 to C60),the bearing capacity and seismic performance have not improved significantly.The bearing capacity of cast-in-place specimen(SC5-C60)was similar to that of prefabricatedprecast specimen(P-SC5-C60).In addition,due to the slip action between the post poured concrete and the prefabricated RC shear wall,the internal force redistribution will occur,which makes the prefabricated specimens had a better ductility and energy dissipation capacity.(2)On the basis of the Ollgaard slip model and the load-slip curve measured by test,considering the influence of the descending stage,a new load-slip model of the intersection surface was proposedis.A finite element nonlinear model considering interfacial bond property was established based on ABAQUS,the details of modeling material,interaction,mesh element and loading and boundary conditions are explained.The load-displacement skeleton curves and load-strain skeleton curves of each specimen test in this paper was calculated,and the calculated results were in good agreement with the experimental results.At the same time,the mechanism of this kind of connection between prefabricated RC shear wall and CFST columns,such as failure mode,load-displacement curve,stress and strain development in the whole process of specimen loading was also analyzed.In the case of the same strength,the shear connector used in this paper was replaced by the connection method proposed by Shirali,and the connection performance of two types of connection was compared.The results show that the shear bond in this paper has better shear resistance and ductility when the number of shear connectors is properly configured.(3)Parameter analysis were carried out to study the influence of parameters such as the strength of the post poured concrete,the distance of the shear connector,the size of the shear connector and the strength of the shear connector on the bearing capacity and ductility factor of the connection between prefabricated RC shear wall and CFST columns by using the above finite element model.Parameter analysis results show that:the failure of specimens can be divided into2 types:failure of shear connector and destruction of concrete on the connector side.When the distance of shear connector shortened from L_w/4 to L_w/6(L_w is the length of the intersection surface),the bearing capacity is increased about 30%,but the average shear force of each shear connector bearing is reduced about 20%.When the cross section thickness of shear connector is increased from 2mm to 4mm,the bearing capacity of the specimen is increased about 90%,and the ductility of the specimen has also been significantly improved.When the shear strength of the shear connector is increased from Q235 to Q420,the bearing capacity of the specimen is increased about 50%,but the ductility is not obviously improved.It shows that the failure mode gradually shifted from the failure of shear connector to the destruction of concrete on the connector side.However,when the strength of the post poured concrete increases,the bearing capacity and ductility of the specimens are not significantly improved.Based on parametric analysis,a design method for the shear bearing capacity of connection between prefabricated RC shear wall and CFST columns was proposed and vertified.