Mechanical Properties Test And Numerical Simulation On Connection Between Multibarrel Tube-confined Concrete Column And Steel Beam

Multibarrel tube-confined concrete column and steel beam structures have the broaddevelopment and application prospect for the advantages such as high bearing capacity ofmultibarrel tube-confined concrete column, better ductility, plasticity, fire resistance andexcellent seismic performance, light weight, high strength and convenient opening of steelbeam. However, the multibarrel tube-confined concrete column and steel beam joint stressstate is complex and diverse. The domestic and foreign research on such joint is laggingbehind, which hinders the development of its application to some extent.In this dissertation, four new circle inner and square outer concrete filled steel tubularcolumn to steel beam joints and one concrete filled steel tubular column to steel beam jointwere designed and tested. The multibarrel tube-confined concrete column to steel beam testspecimens were tested with constant axial compression ratio under the low cycle reciprocatingloads. By adjusting the extending length of vertical ribs and anchorage webs with ribs, thehysteretic performance, strength and stiffness degradation, ductility, energy dissipationcapacity and failure characteristics were analyzed under reciprocating loads. The test resultsshowed that increasing the extending length of vertical ribs can make the plastic hinge moveto the connection of end plate and steel beam flange. It was also shown that anchorage webswith ribs can effectively improve the bearing capacity of the joint. The load versus deflectioncurves was plump, which had stable Joint strength, stiffness degradation stability and betterseismic energy dissipation capacity. By using the method of numerical simulation andtheoretical analysis, the seismic behavior of the suggested connections was analyzed by aNon-linear finite element software ABAQUS. Good agreement can be found from thecomparison of the hysteresis curve, skeleton curve and joint failure mode with theexperimental results. It was indicated that the finite element had a good rationality in theselection of element type, material constitutive model and failure criterion. On this basis, thestress of multibarrel tube-confined concrete column to steel beam joint was analyzed. It wasconcluded that the new joints can effectively transfer the load from beam end to column end.Mises larger stresses of joint core area were shown to mainly distribute at the level of endplate and steel beam flange connections and anchorage webs with ribs. Finally, themechanical property of joint was analyzed with consideration of axial compression ratio andsection steel ratio of concrete filled steel tubular column.