【作者】 张帅；

【导师】 凌育洪；

【作者基本信息】 华南理工大学 ， 结构工程， 2010， 硕士

【摘要】 在北岭地震中,我们发现在地震中发生破坏的节点都是在很低的塑性水平或弹性状态下出现了脆性断裂现象。而基于防止节点焊缝破坏的改进方法大都存在强震后产生较大残余变形的问题,而且由于塑性铰均出现在梁中,构件的破坏往往给结构带来安全隐患,且不易于修复。因此急需一种新型半刚性节点,使框架既能消除节点断裂破坏隐患,又能消除结构残余变形。本文首先通过有限元模拟,分析了节点半刚性对结构性能的改善作用,将其与传统框架进行比较分析;再将自复位性能引入这种半刚性节点中,这种节点采用了可以在轴向压缩过程中通过屈服达到耗能效果的耗能构件,以及平行于梁两侧设置的,为结构提供自复位能力的后张拉钢筋构件。这种后张拉耗能节点用传统材料及其性能,将梁柱的非弹性变形最小化,将大量的破坏能量集中到易于替换的耗能构件上,并且通过自复位性能使结构避免出现残余变形。如果设计得当,这种后张拉耗能节点可以与传统焊接节点拥有相同的强度和刚度。接下来本文对两个3层4跨的、分别具有自复位耗能节点和传统焊接节点的框架进行非线性时程分析,对它们在50年超越概率为10%的地震波下的结构反应进行研究,最后对它们进行比较和评价。通过分析结构我们知道,在往复荷载作用下,后张拉自复位框架的节点耗能由耗能构件(如角钢)的非弹性变形提供,而后张拉钢筋构件和梁柱均保持弹性。相较于传统焊接钢框架,有如下主要优点:(1)拥有自复位能力,从而大大减小了在地震后的残余变形;(2)初始刚度较大,与焊接节点相似;(3)地震下破坏集中在节点的耗能构件处,地震后可以较方便的通过更换节点处的耗能构件来修复节点。更多还原

【Abstract】 In the Northridge earthquake, researchers found that many connections failed in low plastic level or even elastic level due to fracture. Then some optimized approach had been proposed. However, mostly of the new structures have residual deformation after earthquake, and have potential security risks because of their plastic hinge which appeared in beams. Therefore a new type of connection and system, which not only for prevent connection from fracture, but for removing residual deformation for structures, has been proposed.The connection incorporates energy dissipating component that are able to yield in axial compression and tension along with post-tensioned steel elements running parallel to the beam to provide a self-centering response. The post-tensioned energy dissipating connection minimizes inelastic deformation to the beams and columns, requires no field welding with quality workmanship and proper inspection, is made with conventional materials and skills, confines significant damage to the energy dissipating bars which are easily replaced, and is self-centering without residual deformation. In addition a post-tensioned energy dissipating moment-resisting connection properly designed is capable of achieving strength characteristics and stiffness similar to a traditional welded moment-resisting connection.In this thesis, non-linear time-history analyses were performed on a three-story, four-bay steel Moment Resisting Frame with post-tensioned energy dissipating connections to study its response to the seismic environment of ground motions, for 10% probability of exceedance in 50 years. Compared with welded steel frame, the advantages of the new frame are: (1) the connection is self-centering, there is little residual deformation after earthquake.(2) the connection has an initial stiffness similar to that of welded connection;(3) during earthquake, significant damage is confined to the energy dissipating component of connection(such as angles),the connection is easily repaired by replaced the energy component after earthquake.更多还原