框架结构典型梁柱节点的抗连续倒塌性能

Performance of Various Steel Moment Connections Under Progressive Collapse Scenario

摘要:

建立精细化有限元模型，得到了传统栓焊(WUFB)节点、盖板式(WCPF)和狗骨式(RBS)节点在连续倒塌过程中的失效过程，并从能量角度推导了3种节点的动力响应.结果表明：盖板式节点的转动刚度大、拉结能力强，梁机制和悬链线机制承载力均很高，结构的吸能能力好，抗连续倒塌性能优越；狗骨式节点的转动能力强，结构的悬链线效应和吸能能力提高，但结构的外力功增大，抗连续倒塌承载力略有降低.梁柱节点在连续倒塌工况中和地震作用下的受力状态差异大，连续倒塌工况下节点的极限转角远高于节点在地震作用下的转动能力.

Abstract:

Based on computational modelling and energy flow perspective, this paper investigates the failure process and dynamic responses of three types of connections, including web unreinforced flange bolted (WUFB), web cover plated flange (WCPF) and reduced beam section (RBS) under progressive collapse scenario. The results show that the WCPF connection has strong rotational and tensile capacities, and the corresponding beamcolumn assembly has stout flexure mechanism and catenary action. It follows that the beamcolumn assembly with the WCPF connection has high energy absorption capacity and favorable performance under disproportional collapse scenario. The RBS connection has strong rotational capacity, and the corresponding beamcolumn assembly has strong catenary action mechanism and improved energy absorption capacity. However, the RBS connection has reduced flexural stiffness, and thus the external work done by the same gravity load of the corresponding beamcolumn assembly is maximum, which contributes to the slightly lower bearing capacity of the RBS connection under progressive collapse scenario. The study also indicates that the stress states of connections under progressive collapse scenario are quite different from those in seismic tests and that the rotational capacities of connections under progressive collapse scenario are significantly greater than those in earthquakes.