节点域箱形加强式工字形柱弱轴悬臂梁段连接节点的抗震破坏机理及设计对策

发布时间：2018-06-12 03:13

本文选题：节点域箱形加强式连接 + 弱轴连接　；参考：《长安大学》2017年硕士论文

【摘要】：1994年美国北岭地震和1995年日本阪神地震后,人们对工地焊接的梁柱连接节点的抗震性能产生了怀疑,带悬臂梁段拼接的梁柱连接形式得到了重视。带悬臂梁段拼接的梁柱连接节点具有“工厂焊接、现场拼接”的特点,这种连接能够克服现场焊接对气候和焊工技术要求较高、焊接质量难以控制等缺点,耗能能力好,施工速度快。结合课题组前期对节点域箱形加强式工字形柱弱轴连接节点(新型弱轴连接节点)的研究成果,本文设计了两个带悬臂梁段拼接的新型弱轴连接节点试件,一个为标准试件(S-2),另一个为悬臂短梁段变材性试件(S-5),利用试验及ABAQUS有限元分析软件对两试件进行了深入分析。试验研究表明:受焊缝脆断的影响,两试件的延性系数、耗能系数、刚度退化系数等没有表现出明显的规律性。试件延性系数最大值为2.44,说明带悬臂梁段拼接的新型弱轴连接节点的延性性能有待提高;两试件的节点域在最大荷载时刻仍处于弹性阶段,符合“强节点域”的受力特征;试件梁柱连接焊缝及梁梁拼接焊缝的应力均较大,为危险截面,试验过程中出现了梁梁拼接焊缝脆性断裂的情况,这对钢框架节点的抗震十分不利,故在实际工程中要严格保证该部位的焊缝质量。有限元分析表明:S-2拉向及S-5的推、拉向屈服荷载和峰值荷载误差均小于15%,这说明有限元模拟能够较好的拟合试件在循环荷载下的受力特征;有限元模拟所得的延性系数均大于试验所得但仍小于3;蒙皮板厚度对节点的破坏形式影响较大;悬臂梁段采用较高强度钢材能够推迟悬臂连接节点进入屈服阶段的时间,提高钢结构框架的极限承载力;采用梁端加强型悬臂连接节点能够提高节点的承载力,但其延性会有所降低;当悬臂梁段采用栓焊混合连接时,本文推荐悬臂梁段长度取为1-2倍梁高,但不应大于1.6米。
[Abstract]:After the North Ridge earthquake in 1994 and the Hanshin earthquake in Japan in 1995, the seismic behavior of welded Liang Zhu joints on site was questioned, and the form of Liang Zhu connection with cantilever beam segment was paid more attention. The joint of Liang Zhu with cantilever beam segment has the characteristic of "factory welding, spot splicing". This kind of connection can overcome the disadvantages of high requirement of weather and welder technology, difficult control of welding quality, and good energy consumption ability. The construction speed is fast. Combined with the previous research results of the research on the new type of weak axis connection joint (new type of weak axis connection joint) of the box reinforced I-shaped column in the node domain, two new type of weak axis connection joint specimens with cantilever beam segment are designed in this paper. One is a standard specimen, and the other is a cantilever short beam section material changing test piece. The two specimens are deeply analyzed by means of test and Abaqus finite element analysis software. The experimental results show that the ductility coefficient, energy dissipation coefficient and stiffness degradation coefficient of the two specimens do not show obvious regularity due to the brittle fracture of the weld. The maximum ductility coefficient of the specimen is 2.44, which indicates that the ductility performance of the new type of weakly axially connected joints with cantilever beam segments needs to be improved, and the joint domain of the two specimens is still in the elastic stage at the time of the maximum load, which conforms to the stress characteristics of the "strong joint domain". The stress of weld seam and beam joint weld in Liang Zhu connection is large, which is dangerous section. The brittle fracture of beam-beam joint weld appears during the test, which is very disadvantageous to the seismic resistance of steel frame joint. Therefore, the welding quality of this position should be strictly guaranteed in the actual engineering. The finite element analysis shows that the error of tensile yield load and peak load is less than 15 by the push of S-2 and S-5, which shows that the finite element simulation can better fit the stress characteristics of the specimen under cyclic load. The ductility coefficients obtained by finite element simulation are all larger than the test results but are still less than 3; the thickness of the sheathed plate has a great influence on the failure form of the joints; the high strength steel used in the cantilever beam section can delay the time when the cantilever joints enter the yield stage. The ultimate bearing capacity of steel frame is improved, the bearing capacity of joints can be improved by using beam end reinforced cantilever joints, but its ductility will be reduced. It is recommended that the length of cantilever beam should be 1-2 times the height of beam, but should not be more than 1.6 meters.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391;TU312.3

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