悬臂梁段不同拼接方式下延性节点静力性能分析

为了解决装配式钢结构的抗震问题,提出3种适用于模块化装配式钢框架的带Z字形悬臂梁段拼接的梁柱节点,通过拼接区的滑移或者削弱梁段的塑性变形实现节点良好的延性性能.为减少强震作用对梁柱连接焊缝的破坏,对3种不同的节点提出了各自的抗震设计要求.在对3组试件进行足尺静力试验的基础上,对节点进行了单调加载有限元分析.获得了节点的弯矩-转角曲线以及节点的破坏模式,并和试验结果进行了对比,得到了接触面摩擦力和螺栓拉力的变化规律.通过推导的简化计算公式对节点的初始转动刚度、滑移荷载和屈服荷载进行了计算.结果表明:节点静力加载的破坏模式为靠近拼接区域的悬臂梁下翼缘或者削弱梁段单独或者同时发生较大的局部屈曲变形,节点在破坏前经历了充分的塑性变形,属于延性破坏,3种试件都有良好的延性性能和塑性转动能力.节点简化计算公式得到的结果和试验结果吻合良好.

Analysis on Static Behavior of the Ductile Connections With Different Cantilever Beam Splices

In order to solve the seismic problem of prefabricated steel structure, three kinds of modularized prefabricated steel frame connections with Z-shaped cantilever beam splicing were presented. The connections can utilize the slipping of splicing and the plastic deformation of reduced beam section to achieve good ductility performance. The seismic design requirements of the three different connections were proposed in order to reduce earthquake damage of the beam-column joint weld seam. Based on the static experimental results of three full-scale specimens, the static finite element analysis was carried out. The moment-rotation curves and the failure modes of the connections were obtained, and the results were compared with experimental results. The change rules of the friction between contact surfaces and the bolt tension force are obtained. The initial rotation stiffness, slipping load and yield load of the connections were calculated by deriving the simplified calculation formula. The results show that the failure modes of connections under static loading are the large local buckling deformation of cantilever beam bottom flange or reduced beam section. The connections undergo large plastic deformation before failure, and the failure mode is the ductile failure. Three specimens have good ductility and plastic rotation capacity. The results obtained by the simplified calculation formula of the connections are in good agreement with the experimental results.