【作者】 徐红杰；

【导师】 陶忠；

【作者基本信息】 昆明理工大学 ， 防灾减灾工程及防护工程， 2010， 硕士

【摘要】 近年来随着我国高层和超高层钢结构建筑的应用越来越多,钢结构梁柱节点的抗震性能问题越来越突出,如果处理不当,具有良好抗震性能的钢结构建筑在地震中也可能遭受大的震害,美国北岭地震和日本阪神地震时钢结构节点的震害深刻地表明了节点延性设计的重要性。1994年美国北岭地震和1995年日本阪神地震中大量的梁柱节点发生了脆性破坏,造成这种现象的原因可以概括为以下几个方面：与地震地面运动有关的因素、与设计有关的因素、与焊接有关的因素、与钢材有关的因素和一些其它因素。防止梁柱节点脆性断裂的措施也应该从选材、设计、施工和检验方面考虑。地震后对节点进行的改进主要表现在：(1)减小应力集中。采用的方法有：改进焊接工艺孔、对梁翼缘焊接垫板进行处理、严格焊接工艺要求,减少焊接缺陷、清除含裂纹部分、构件部分替换。(2)将塑性铰外移。采用的方法有：局部加强措施和局部削弱措施。焊接盖板节点和焊接梁腋节点属于局部加强措施；狗骨型节点和带长槽型节点属于局部削弱措施。试验和有限元分析表明,这些节点具有良好的抗震延性。此外,钢结构节点抗震延性的影响因素还包括：柱腹板横向加劲肋、节点域屈服、强柱弱梁要求、弱轴柱的弯曲、侧向扭转和局部屈曲、深柱、箱型柱、组合楼板、温度效应、动力效应。本文以FEMA-SAC联合机构做过的试验为基础,探讨了这些因素会对节点的抗震延性产生怎样的影响,并给出了这些因素作用下,节点要产生良好的抗震延性所应满足的条件。所有节点的屈服机制和破坏模式对其抗震延性起决定性作用。屈服机制能够在节点承载力下降或破坏之前为大的塑性转动提供位置和塑性变形的来源,破坏模式导致承载力下降和节点破坏。本文给出了常见节点的屈服机制和破坏模式。文章还将中国规范与国外的一些研究成果进行比较,指出了尚未被考虑影响节点抗震延性的设计参数,同时对中国规范关于钢结构节点抗震延性的发展方向进行了展望。更多还原

【Abstract】 As more and more multistoried and tall steel structures appeared in China recent years, seismic performance of beam-column connections for steel structures is becoming more and more predominant, if not handled properly, steel structures which are regarded as having good seismic performance may suffer greet demage, the seismic damage in Northridge and Hyogoken-Nanbu earthquakes of beam-column connections proved the importance of ductility design for connections deeply.Plenty of beam-column connections occurred brittle failure in American Northridge earthquake in 1994 and Japan Hyogoken-Nanbu earthquake in 1995, the causes of this phenomenon can be summarized as follows:issues related to the earthquake ground motion; issues related to design; issues related to welding; issues related to steel and other issues. The measures to prevent brittle failure of beam-column connections should take selection of materals, design, construction and inspection into account.The improvements of connections after the earthquakes are mainly on:(Ⅰ) Reduce the stress concentration. The methods that can be used are:improve the cope hole; deal with the backing strip used for beam flange; strict the requirements for welding; reduce welding defects; remove the cracked parts; partial substitution of components. (Ⅱ) Remove the plastic hinge away from the column face. The methods that can be used are:local reinforcement measures and local reducing measures. Haunched connections and coverplate connections are included in local reinforcement measures, reduced beam section connections and slotted web connections are included in local reducing measures. Results of experiments and finite-element analysis manifest that these connections have good anti-seismic ductility.In addition, the factors influencing anti-seismic ductility of steel connections also consist of column webs transverse stiffener, panel zone yielding, strong column weak beam requirements, weak axis column bending, lateral torsional and local buckling, deep columns, box columns, effect of composite slabs, thermal effects, dynamic effects. This article discuss how these factors influecne anti-seismic ductility of connections based on the experiments done by the joint establishment of FEMA-SAC, give the requirements in order to get good anti-seismic ductility of connections influencing by these factors too.The yield mechanisms and failure modes dominate the anti-seismic ductility of all connections.Yield mechanisms provide a location and source of yield deformation where large plastic rotations can occur before fracture or deterioration of connection resistance can develop. Failure modes result in fracture and loss of resistance. The yield mechanisms and failure modes of the common connections are given in this article.By comparing Chinese codes with the results of exotic researchs, the design parameters which influence anti-earthquake ductility of connections not considered in Chinese codes are given, this thesis also outlooks the development direction of Chinese codes about anti-seismic ductility of steel structure connections.更多还原