柱脚可抬起的连柱钢支撑结构抗震性能研究

发布时间：2018-01-28 20:32

本文关键词： 可抬起柱脚耗能段可替换连柱钢支撑有限元　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：连柱钢支撑结构是一种新型的双重抗侧力结构,由耗能梁段连接独立的支撑框架构成。在地震作用下由耗能梁段率先进入弹塑性耗散地震能量,非耗能构件仅在结构变形较大时发展塑性,具有明显的屈服时序。震后只需将连柱钢支撑结构中损伤的耗能段移除,支撑框架便可利用自身的弹性刚度恢复到原来的位置,修复成本大大降低。将可抬起柱脚应用于连柱钢支撑结构中,能够使耗能段在同样水平荷载作用下的竖向变形增大,耗能段耗散的能量增加,更大程度上实现耗能段集中耗能。为了研究柱脚可抬起的连柱钢支撑结构的抗震性能,本文应用ABAQUS有限元分析软件模拟分析了柱脚可抬起的连柱钢支撑结构的抗震性能,主要做了以下研究工作:(1)应用SAP2000有限元分析软件设计了1栋5开间3跨共15层的连柱钢支撑结构,并选取底部三层中间支撑跨结构作为采用实体单元分析的BASE试件。(2)详细介绍了应用ABAQUS有限元分析软件对BASE试件的建模过程,通过对已有的两个试验研究的模拟验证了整个建模过程的可靠性。(3)对比分析了中柱采用可抬起柱脚的试件和柱脚采用普通刚接形式的试件的抗震性能。结果表明:中柱采用可抬起柱脚的试件的破坏模式更为理想、耗能机制更加合理、延性以及耗能能力更好。(4)设计了3组柱脚可抬起的连柱钢支撑结构试件,分别考察跨度、层高和支撑框架钢材强度等级对结构抗震性能的影响。结果表明:当结构的高跨比在0.4~0.5范围内取值时,结构的抗震性能可以发挥到最佳。提高支撑框架钢材强度等级,试件的极限承载力提高、剩余刚度增大、破坏程度减轻,有利于震后修复,但试件延性降低。(5)利用等能量原理将柱脚可抬起的连柱钢支撑结构的正向骨架曲线简化为三折线,分别考察跨度、层高和支撑框架钢材等级对结构抗震性能的影响,确定结构耗能段可替换的层间侧移角范围。结果表明:对于耗能段采用Q235B级钢,支撑框架采用Q345B级钢的柱脚可抬起连柱钢支撑结构可以取耗能段可替换层间侧移角的下限为1/550,上限为1/130。对于支撑框架分别采用Q235B、Q390B、Q420B、Q460C、Q550C钢材的试件的耗能段可替换层间侧移角范围的上限分别下降了31%、提高了4%、19%、32%、42%。
[Abstract]:The column steel bracing structure is a new type of double lateral force resisting structure, which is composed of an independent bracing frame connected with the energy dissipation beam section. Under the earthquake action, the energy dissipation beam section first enters the elastic-plastic dissipative seismic energy. The non-energy dissipation member develops plasticity only when the deformation of the structure is large, and has obvious yield sequence. After the earthquake, it is only necessary to remove the damaged energy dissipation section of the column steel braced structure. The braced frame can be restored to its original position by using its elastic stiffness, and the repair cost is greatly reduced. It can increase the vertical deformation of the energy dissipation section under the same horizontal load, and increase the energy dissipation of the energy dissipation section. In order to study the seismic behavior of the column steel braces which can be lifted with column foot, the concentrated energy dissipation of the energy dissipation section is realized to a greater extent. In this paper, ABAQUS finite element analysis software is used to simulate and analyze the seismic behavior of the column steel braced structure which can be lifted with column foot. The main research work is as follows: (1) using SAP2000 finite element analysis software, we design a 15 story steel supporting structure with 5 open spaces and 3 spans. And select the bottom three layers of intermediate bracing cross-structure as the BASE specimen with solid element analysis. The modeling process of BASE specimen using ABAQUS finite element analysis software is introduced in detail. The reliability of the whole modeling process is verified by the simulation of two existing experiments. The results show that the failure mode of the specimens with the raised column foot is more ideal than that of the specimen with the ordinary rigid joint in the middle column, and the seismic behavior of the specimen with the lifting column foot is compared and analyzed. The energy dissipation mechanism is more reasonable, the ductility and energy dissipation ability are better. The influence of story height and steel strength grade of braced frame on the seismic performance of the structure. The results show that when the ratio of height to span of the structure is in the range of 0.4 ~ 0.5. The ultimate bearing capacity of the specimens is increased, the residual stiffness is increased, and the damage degree is reduced, which is beneficial to the post-earthquake repair. However, the ductility of the specimen is reduced. 5) the forward skeleton curve of the column steel braced structure which can be lifted with column foot is simplified to three broken lines by using the principle of equal energy, and the span is investigated separately. The influence of story height and steel grade of braced frame on the seismic performance of the structure and the range of interlayer lateral displacement angle of the energy dissipation section of the structure are determined. The results show that Q235B grade steel is used for the energy dissipation section. The column foot of Q345B grade steel can be lifted up in the bracing frame. The lower limit of the displacement angle of the energy dissipation section can be taken as 1/550. The upper limit is 1 / 130. For the supporting frame, Q235BU Q390BU Q420BU Q460C is used respectively. For Q550C steel, the upper limit of the range of alternative interlayer lateral displacement angle of the test piece of Q550C steel is decreased by 31and the upper limit of the displacement angle range has been decreased by 31s, which has increased the energy consumption section of Q550C steel.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU973.31

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