十字形钢管混凝土柱-钢梁节点抗剪性能研究

Shear behavior of concrete-filled steel tubular cross columns and steel beam joints

为建立侧板连接十字形钢管混凝土柱-钢梁节点的剪切屈服机制,揭示节点传力机理,按1∶2比例设计新型节点抗剪受力模型,利用有限元软件ABAQUS建立低周往复荷载作用下的精细化数值分析模型,观察其破坏模式及传力机制,考察轴压比和侧板厚度对节点抗剪承载力的影响。结果表明:节点模型表现为节点核心区剪切破坏,核心混凝土受力符合斜压杆机理,节点的受力机理为钢桁架、混凝土主斜压杆和约束斜压杆的综合作用;轴压比和侧板厚度对新型节点受剪承载力有一定影响,增大轴压比或侧板厚度,节点受剪承载力提高,增加侧板厚度可以提升节点初始刚度;新型节点具有良好的延性及耗能能力,满足结构抗震设计要求。

Cross-shaped steel pipe concrete column in order to establish a lateral plate connection of steel girder node shear yield mechanism,reveal the node force transmission mechanism,the new node shear stress model is designed according to the proportion of 1:2,the finite element software ABAQUS is used to establish the low cycle loading week refinement numerical analysis model,observe the force transmission mechanism,failure mode and examined the axial compression ratio and the thickness of the side panel on the influence of shear bearing capacity of the node.The results show that the joint model shows the shear failure of the core area of the joint,and the stress of the core concrete conforms to the baroclinic bar mechanism.The stress mechanism of the joint is the combined action of the steel truss,the main baroclinic bar of concrete and the constrained baroclinic bar.The axial compression ratio and the thickness of the side plates have certain effects on the shear capacity of the new joints.The shear capacity of the joints increases with the increase of the axial compression ratio or the thickness of the side plates,and the initial stiffness of the joints increases with the increase of the thickness of the side plates.The new joint has good ductility and energy dissipation ability,and meets the seismic design requirements of the structure.