可更换延性耗能连接组件的钢框架节点抗震性能研究

SEISMIC BEHAVIOR OF STEEL FRAME CONNECTIONS WITH REPLACEABLE HIGH DUCTILITY AND ENERGY DISSIPATION COMPONENTS

  • 摘要: 为满足高烈度、高人口密度地区对高延性和高耗能能力装配式钢结构的迫切需求,采用高性能低屈服点钢材代替传统钢材来制作钢框架节点连接组件,利用高强度螺栓与主体结构连接,实现预制装配功能、"延性耗能保险丝"功能、震后可更换功能的叠加。采用通用有限元软件ABAQUS建立非线性全接触有限元模型,结合国内外已有的钢框架全螺栓连接节点循环加载试验,验证建立的数值模型对模拟局部屈曲以及螺栓滑移现象的准确性。在此基础上,通过建立三类典型带连接组件的全螺栓连接钢框架节点数值模型,采用三种不同材料LYP100、LYP160和Q235制作连接组件,对比其承载性能、滞回行为、累积塑性应变以及耗能能力等,深入探讨采用低屈服点钢材连接组件钢框架节点的工作机理。结果表明:连接组件采用低屈服点钢材,可改变节点破坏模式,使塑性累积变形主要集中在连接组件上,耗散大部分能量(90%左右),避免主体结构过早进入塑性阶段,有效发挥"延性耗能保险丝"作用;带低屈服点钢材连接组件节点的耗能能力高于带普通钢材连接组件的节点;当节点转角达到0.045 rad时,低屈服点钢材连接组件的最大伸长率远小于低屈服点钢材极限强度所对应的应变,说明连接组件仍具有较大的变形空间,不会发生提早断裂破坏,有效提高节点延性。

     

    Abstract: In order to satisfy the urgent requirement of assembled steel structures with high ductility and energy dissipation capacity for the areas with high seismic intensity and population density, high performance low yield point steel is used for the connecting components of steel frame connections instead of ordinary steel. Then, the combination of prefabricated assembly function, ‘ductile energy dissipation fuse’ function and post-earthquake replaceable function is achieved with utilizing high-strength bolts. The non-linear finite element model of ABAQUS proves to be correct in simulating local buckling and bolt slipping phenomena based on published steel frame bolted connection tests at home and abroad. Based on this method, three types of bolted steel frame connections with connecting components using three different materials LYP100, LYP160 and Q235 were established. Their load-carrying capacity, hysteretic behaviour, cumulative plastic strain and energy dissipation capacity were compared, and the mechanism of connections with low yield point steel components was discussed. The results showed that using low yield point steel connecting components could change the failure mode of connections, make the plastic cumulative deformation mainly concentrate in connecting components, dissipate most of energy (around 90%), avoid the main frame encountering plasticity too early and effectively play a role of "ductile and energy dissipation fuse". The energy dissipation capacity of connections with low yield point steel components was higher than that of connections with ordinary steel components. When the rotation of connections reached 0.045 rad, the maximum elongation of low yield point steel components was much smaller than limit value, indicating that the components still had deformation capacity without premature fracture damage, which effectively improved the ductility of connections.

     

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