【作者】 王想军；

【导师】 张文元；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2006， 硕士

【摘要】 钢材具有很好的延性,所以一直以来,人们认为在强震中钢框架能够表现出很好的强度和延性来抵抗地震荷载。在1994年美国的Northridge地震和1995年日本的阪神地震中,传统的钢结构梁柱连接节点中发生了很多脆性裂纹,这些裂纹大多产生在梁端翼缘焊缝处,随后,朝柱翼缘和梁腹板处延伸。节点在产生塑性变形时能消耗相当一部分从地震中吸收的能量,而脆性裂纹的出现阻止了焊接节点塑性的发展。北岭地震以后,人们通过大量的试验研究和理论分析来提高梁柱节点的性能,其提高的主要途径是增强节点或者削弱梁段来提高梁的塑性变形能力,从而耗散地震能量。本文所研究的梁端翼缘扩大型节点是加强型节点中的一种,其中包括翼缘放大型和翼缘侧板加强型两种类型,尽管此前已经有人提到过侧板加强型节点,但试验研究很少。本文通过四个梁端翼缘扩大型梁柱节点在地震荷载作用下的试验研究,对其破坏模式和抗震性能进行了研究,主要内容包括:1.参照现已研究比较成熟的翼缘削弱型梁柱节点的削弱部位翼缘几何尺寸,确定了扩大翼缘的长度。根据转移塑性铰的原则,算得合理的翼缘宽度尺寸。并通过Ansys的分析验证,从理论上保证了试验节点截面的合理性。2.进行梁端翼缘扩大型钢结构梁柱节点在往复荷载下的伪静力试验。试验测得了梁端荷载、位移、柱子转角和节点域剪切变形,从而得到了滞回关系曲线;同时也测得了梁翼缘和腹板上应变数据,并对试验现象进行了观测。3.基于试验结果,分析了梁端翼缘放大型节点和侧板加强型节点在地震荷载作用下的破坏机制、承载力、耗能能力、变形能力、刚度以及梁翼缘和腹板上应力的分布状态。对两类节点抗震性能的比较发现,所有节点都能有效的将塑性铰外移,但翼缘放大型节点在抗震性能和转移塑性铰方面优势更加明显。更多还原

【Abstract】 Steel moment-resisting frames were believed to be able to develop the strength and ductility required to resist strong seismic loading because steel is ductile. However, widespread and unpredicted brittle fractures have been found in weld steel beam-column connections (weld-flange-bolted-web connections) of moment-resisting frames shaken during the Northridge earthquake in 1994 and the Kobe earthquake in 1995. Such fractures were most often initiated at the bottom flange weld and propagated into the column flange and the beam web. The brittle failure prevents the welded moment connections from exhibiting the inelastic behaviour expected to resist earthquake loading. Since the Northridge earthquake, numerous experimental and analytical studies have been conducted to improve connection performance. The improvement is based mainly on strengthening the connection or weakening the beam to develop stable inelastic behaviour that will dissipate a large portion of the energy absorbed from the earthquake.The Beam-to-column connection with beam-end horizontal haunch is a kind of reinforced beam-to-column connections. It includes two categories of connections. One of the two categories is flange-widened connections. The other category is the side flange-reinforced connections. Though the side flange-reinforced connection has been mentioned, yet very limited test data are available. Four specimens were fabricated and tested to clarify the behaviour and failure mode of the connections with beam-end horizontal haunch under seismic loading. The main contests are listed as follows:Firstly, ampliative flange length was determined referring to reduced beam section connections which have had ripe theory. The nessesary width of reinforced flange was calculated on the basis of moving the location of the beam plastic hinge away from the face of the column to the narrowest section of the beam flange. Also, the decided flange-enlarged sections were proved to be appropriate by ansys ansysis.Secondly, hypocritical statics test about connections with beam-end更多还原