新型PEC柱-钢梁端板连接组合框架层间抗震机理试验研究

Test Study on Seismic Mechanism of Interstory Substructure of Innovative PEC Column-steel Beam Frame with End-plate Connection

为研究新型卷边PEC柱-钢梁外伸端板连接组合框架结构的层间抗震机理,按1∶2缩尺设计了1榀组合框架层间子结构模型试件并进行水平低周往复荷载试验。基于试验现象和测试数据,分析了试件结构的破坏过程与破坏模式、滞回特性、刚度退化、耗能能力、变形模式等抗震性能。结果表明:试件结构最终破坏模式为端板附近梁截面充分屈服形成塑性铰的理想塑性破坏机构;试件整体与层间位移延性系数μu=3.74和最大等效粘滞阻尼系数(ζeq)max=0.325,具有良好抗震延性和耗能能力;试件结构整体性好,水平抗侧刚度沿高度分布均匀,水平位移分布规律表现为理想的倒三角弯剪型变形模式;试件结构整体与层间侧移和节点转角均超过大震层间侧移限值的1/30,即试件结构具有良好的抗倒塌能力。

Superior collapse-prevention performance of the building structure can maintain its abundant integrity to realize the design target of collapse prevention at maximum considered earthquake （ MCE ） level. To investigate the seismic mechanism of innovative PEC column-steel beam composite frame with end-plate and pretension penetrating bolts connection, a 1/2 scale test specimen of inter-story substructure was designed and tested under lateral low-cycle reserved loading. Based on the test observation and measurements, the seismic performance including the failure process and failure mode, the hysteretic property, lateral stiffness degradation, energy dissipation capacity and drift deformation pattern were analyzed. Test results showed that the failure mode is primary induced by the plastic hinge of beam section adjacent to end plate. The displacement ductility coefficient and maximum equivalent viscous damping ratio of the specimen are 3.74 and 0. 325 respectively, and the specimen owns better seismic ductility and energy-dissipation capacity. The drift pattern as ideal inverted triangle pattern of flexure-shear type is formed due to its excellent integrity and lateral stiffness is evenly distributed along its height. The interstory drift ratio and connection rotations all surpass the drift limit （1/30） of maximum consideration earthquake, correspondingly the specimen owns sound collapse prevention capacity.