Research On Seismic Behavior And Design Method Of Composite Frame With Reinforced Concrete Columns And Steel Beams

Reinforced concrete columns and steel beams composite structure(RCS), is atypical composite structure. RCS composite frame integrated the advantages of thereinforced concrete structure and steel structure. It can make full use of material and agood seismic performance. It is a kind of low cost and high efficiency structure. Manyresearches had been researched on RCS composite structure. In this paper, the seismicperformance, the failure forms, the shear mechanism of joints panel as long as theseismic design based on structure performance were studied.Six RCS composite joints were designed and tested under low reversed cyclicloading. Bearing capacity, the failure form, strength and stiffness degeneration,hysteretic performance, ductility and energy consumption of RCS composite joints withdifferent details were studied. All the six specimens were broken in the joint panel.Through the previous research results and test results in this paper, three failure formsof RCS composite joint were put forward, local failure, shear failure and bearing failure.The joints with different failure forms were simulated by ABAQUS, then the failuremechanisms were analyzed. And the influence law of different parameters on differentfailure forms was studied systematically.Parameter analysis of shear bearing capacity were conducted on RCS compositejoints panel, the parameters include the strength of concrete, steel beam web plate, theaxial compression ratio, degree of flange removal and stirrup ratio. According to theanalysis, the influence law of various parameters on RCS composite joints panel wasobtained. Based on the assumption that concrete deformation inner and outer panel wereconsistent, RCS composite joints shear model was put forward. The shear mechanismsthat the steel web pure shear and concrete diagonal compression strut model were bearthe horizontal shear capacity. According to the mechanism, RCS composite joint shearcapacity was put forward and checked.A RCS composite frame was designed and tested under low reversed cyclicloading. The bearing capacity, story drift, ductility, strength degeneration, stiffnessdegeneration and energy consumption of RCS composite frame were studied. The RCScomposite frame has good ductility, energy consumption and seismic performance. TheRCS composite frame was simulated by ABAQUS and Open SEES. The stressdevelopment of steel beam and reinforced concrete column were analyzed by ABAQUS.Parameter analyses were conducted on RCS composite frame by Open SEES.The strong-column weak-beam(SCWB) criterion of all-concrete and all-steelmoment resisting frames are introduced. The updated SCWB criterion is proposed. Thestudy of performance index and seismic design method on RCS composite frames wassuggested. Then the research on the premise of performance design and ensureearthquake fortification goal and different performance levels of distortion permissiblevalue was conducted. The performance level of RCS composite frame was divided intofive classes, combined with three level of seismic action, putting forward three groupsof structure performance target group, matched the quantitative index of the reinforcedconcrete column, and referd to related provisions of foreign codes, then determined thestory drift limit of the reinforced concrete frame under different performance level. Inthis paper, the design based on the displacement was put forward for the RCS compositeframes, taking a regular structure as example, explained how the seismic design methodbased on displacement implement in particular in this new structural system.