装配式钢框架节点带Z字形悬臂梁段和削弱梁段连接的抗震性能研究

为研究装配式钢框架节点带Z字形悬臂梁段和削弱梁段拼接的抗震性能，采用拼接区和削弱梁段共同耗能设计了4个试件。对4个试件进行了低周往复加载试验以及单调及往复加载的有限元分析。通过对试件的破坏模式和拼接区的滑移情况进行了分析，研究了以梁端弯矩 转角表征的滞回曲线、骨架曲线、耗能能力、转动能力等。结果表明：试件主要利用削弱梁段的塑性变形和拼接区的滑移实现耗能；其失效模式为螺孔或者焊缝处撕裂、削弱梁段处局部屈曲和削弱梁段处弯扭失稳；为保证节点充分发挥耗能能力，应增大削弱梁段处的侧向约束，防止发生弯扭失稳；为满足现场安装方便的要求和应对工厂加工精度不足的现状，可以在悬臂梁段翼缘开大孔；为降低工厂加工难度，可以将方钢柱内隔板替换为三角形垂直加劲肋。

Seismic behavior of prefabricated steel frame connection withZ-shaped cantilever beam and reduced beam section

A kind of prefabricated steel frame joint with Z-shaped cantilever beam and reduced beam section is presented. The basic specimen is designed based on the energy dissipation of spliced section and reduced beam section, and four specimens are obtained by changing the key parameters. Low cycle reversed loading tests of four such specimens were conducted, and the static and quasi-static finite element analysis were carried out. The failure modes and splicing slippages of specimens were analyzed; the hysteresis curves, skeleton curves, energy dissipation capacity and rotational capacity of specimens were obtained. The results show that the joint can utilize the plastic deformation of reduced beam section and the slipping of splicing to dissipate energy effectively. The failure modes of the connections are tearing of bolt hole section or weld seam, local buckling of the reduced beam section and torsional-flexural buckling of the reduced beam section. In order to ensure the energy dissipation performance of the connection, the lateral restraint of the reduced beam section should be strengthened to prevent the occurrence of torsional-flexural buckling. It is practical to use the oversized bolt holes in cantilever beam flange in order to meet the requirements of convenient on-site installation and deal with the status of the processing precision deficiency. The triangular vertical stiffeners can be used instead of internal diaphragms in order to reduce the processing difficulty.