| The tubed reinforced concrete structure not only inherits the characteristics of high bearing capacity and good seismic performance of concrete filled steel tube structure,but also has the advantages of convenient construction,good fire resistance and full use of high strength material properties.It has been widely used in many fields such as high-rise and super high-rise buildings,bridge structures,underground engineering and large public buildings.At present,domestic and foreign scholars have relatively perfect research on the mechanical properties of tubed reinforced concrete columns and joints,but there are few studies on the tubed reinforced concrete frame structure system,and the seismic design basis of the structural system is insufficient.In order to further promote the application of tubed reinforced concrete system,this paper designs a plane frame of circular tubed reinforced concrete column-RC beam,and carries out experimental research and theoretical analysis on its seismic performance.The main work and research results are as follows :(1)The quasi-static test of circular tubed reinforced concrete column-RC beam plane frame is carried out.According to the overall horizontal load-displacement hysteresis curve,steel strain-displacement curve,steel tube strain-displacement curve and failure mode obtained from the test,the skeleton curve,strength degradation,stiffness degradation,displacement ductility,energy dissipation performance and stress development law of steel bar and steel tube of the specimen are analyzed.The failure mechanism of the specimen and the hinge sequence of beam and column are explored,and the seismic performance of the specimen is scientifically summarized and evaluated.(2)ABAQUS software is used to simulate the test.On the basis of verifying the correctness of the finite element model,the influence of axial compression ratio,steel tube yield strength,concrete strength,diameter-thickness ratio,column-beam strength ratio,beam-column linear stiffness ratio and floor on the seismic performance of the frame is further studied.According to the results of parameter analysis,the design suggestions of the frame are given.(3)The modeling methods of three kinds of joint domain analysis models are introduced.Three kinds of joint models are established by Open Sees software to simulate the seismic performance of the specimens.The simulation results of the three joint models are in good agreement with the test.Among them,the BCJE joint model considering the shear deformation and steel slip in the joint area is more suitable for simulating the seismic performance of the frame in this paper.On the basis of verifying the rationality of the fiber model,the finite element model of the frame with floor slab is established to study the influence of floor slab on the seismic performance of the frame.(4)The PKPM software is used to design an example of circular tubed reinforced concrete column-RC beam frame in 8 degree(0.2g)area.Taking the frame joint domain as the research parameter,through the time history analysis,IDA analysis,and seismic vulnerability analysis of the frame example with floor slab,the time history displacement curve,interlayer displacement and failure probability under different performance states are compared.Through the analysis results of different optimization design schemes,the optimization design suggestions for the frame structure are put forward. |
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