中文摘要：

为了进一步研究新型PEC柱-钢梁T形件焊接加强型中节点的抗震性能,考虑柱轴压力、PEC柱布置方式和钢板组合截面类型等设计参数,设计制作了4个中节点1∶1.6缩尺模型试件,并对其进行水平低周往复荷载试验,观测记录了各试件试验中钢材屈服或屈曲与混凝土裂缝与压溃现象,得到试件的荷载-位移滞回曲线和破坏模式。根据试验结果分析了试件的承载能力、节点连接转动刚度退化、耗能能力和节点传力机理等抗震性能。结果表明：PEC柱组合截面翼缘采取卷边措施增强了核心区混凝土的约束作用;PEC柱轴压力提高了节点的初始转动刚度,而受力变形过程中的二阶效应降低了其抗弯承载力并加快了梁截面进入屈服的损伤进程;所有试件均表现出良好的自复位功效;所有试件破坏模式均为加强T形件端部焊缝附近梁截面形成塑性铰,更好地满足＂强节点弱构件＂的设计要求。上述结果有助于对PEC柱-钢梁节点抗震性能的认识,可为PEC柱-钢梁组合结构设计规范制订以及工程应用提供参考。

英文摘要：

In order to further investigate node seismic performance of new partially encased composite（PEC）Column-Steel Beam with T-shape welding strengthened connection,4model specimens of 1∶1.6 scale were designed and fabricated by taking into account some parameters,such as axial compression,PEC column layout and type of thin-walled cross section etc.Horizontal low cycle load experiment was carried out,the steel yield or buckling and the phenomenon of concrete cracking and collapse were observed and recorded for each tested specimen.Finally,load-displacement hysteretic curve and failure mode of specimen was obtained.Based on experimental results,specimens＇ global behaviors were studied,including load-carrying capacity, node connection rotation stiffness degradation,energy dissipation capacity and node force transfer mechanism etc.Results show that PEC column cross section flange crimping can well improve concrete constraint in core area;PEC column axial pressure increases the initial rotational stiffness of node;the two-step effect during deformation process of forc reduces itsflexural bearing capacity and accelerates beam cross section damage process.All tested pieces show good self reset effect.All failure modes of specimens are the formation of plastic hinge of beam cross section near the end of the T-shape,which meets the seismic requirement of＂strong column,weak beam＂.Above results are helpful to understand the seismic performance of PEC column and steel beam node and may provide the references for specification establishment and engineering application of PEC column-steel beam structure.