新型卷边钢板组合PEC柱-钢梁中节点抗震性能试验研究

Experimental study on seismic performance of interior connections between new crimping thin-walled built-up section PEC column and steel beam

为研究新型卷边钢板组合PEC柱-钢梁连接节点的抗震性能,采用端板预拉对穿高强螺栓连接方式,以组合柱布置方式与梁端削弱截面设置作为设计参数,设计制作了3个中节点1∶1.6缩尺模型,对其进行低周循环荷载试验,重点分析试件的滞回性能、承载能力与转动刚度退化、延性与耗能能力和破坏模式。试验结果表明:新型卷边钢板混凝土组合PEC柱较好满足了"双向等刚度"的要求;预拉对穿螺栓的设置使节点域充分实现混凝土斜压带传力功效,相应降低对节点域钢柱腹板的抗剪要求,且所有试件均表现出不同程度的自复位功能与良好的耗能能力;所有试件在承载能力下降至85%之前,节点转动均超过了0.035弧度;试件破坏模式为钢梁削弱截面或连接部位附近截面屈服。

To investigate the seismic performance of new partially encased composite( PEC) column fabricated with crimping thin-walled built-up section—steel beam connection,end plate connections with pre-tensioned high-strength penetrating bolts were adopted. Using layout form of columns and reduced cross-section as the design parameters,three1∶ 1. 6 specimens were designed and fabricated. Quasi-static cyclic lateral loads were applied on the specimens to study the hysteretic behaviors,degradation of strength,flexural stiffness,energy-dissipation capacity,the ductility property and the failure mode. Test results show that new PEC columns can meet the requirement of bidirectional equal stiffness.The force-transfer mechanism of concrete equivalent strut in the panel zone alleviates shear demand of steel web,meanwhile all specimens show self-centering functions and sound energy-dissipation capacity to different extents. The rotational angles of all specimens exceed 0. 035 rad when the bearing capacity is below 85% ultimate strength,which validates their superior collapse resistant capacity. the failure modes are mainly induced by the yielding in the reduced cross-section or near the welding position of steel beam.