附加刚度屈曲约束支撑框架抗震性能分析

发布时间：2018-06-05 12:40

本文选题：附加刚度屈曲约束支撑 + 拼装式　；参考：《东南大学》2015年硕士论文

【摘要】：地震作用下,框架结构某层层间位移角可能远大于其他楼层,从而形成薄弱层,在P-△效应的作用下结构的抗倒塌能力降低。为此,本文提出一种新型的结构体系——附加刚度屈曲约束支撑(Buckling Restrained Brace, BRB)框架,该结构在地震作用下,楼层层间位移角的分布均匀性可以通过附加刚度进行控制,而且附加刚度可以作为BRB低周疲劳断裂的“保险丝”。本文从构件层次的试验验证了附加刚度BRB的滞回特性;从结构层次的有限元模拟分析了该新型体系的抗震性能,主要研究工作如下：(1)分析了附加刚度BRB的组成部分及工作机理,提出一种新型轻质、拼装式的附加刚度BRB的构造方式,通过构件的拟静力试验得出附加刚度BRB滞回曲线,分析内外筒不对齐和螺栓滑移等因素对构件性能的影响：基于双折线弹塑性模型,比较了BRB、自复位BRB、附加刚度BRB的等效粘滞阻尼比；基于opensees的二维杆系简化模型可较好的模拟出附加刚度BRB的滞回性能。(2)依据美国抗震规范设计了9层支撑铰接BRB框架和附加刚度BRB框架,基于材料叠加和单元叠加,提出了附加刚度BRB在结构中的简化建模方式；通过对BRB框架和附加刚度BRB框架在20条设防地震波的弹塑性时程分析,表明附加刚度BRB能有效控制层间位移角分布的不均匀,并提出附加刚度BRB框架启动位移应取BRB框架层间位移角中位值对应的支撑位移；为解决附加刚度引起的结构加速度和基底剪力过大的问题,建议节点处采用摩擦阻尼器的“保险丝”装置。(3)阐述多自由度体系向单自由度体系等效的理论基础,在比较不同模型特性的基础上选择了Ibarra-Krawinkler模型,采用经典的单自由度体系建立了含P-△效应的附加刚度单自由度体系：提出基于“二分法”的增量动力时程分析倒塌点搜索方法,通过该方法对附加刚度单自由度体系进行了参数分析;为对比不同周期附加刚度单自由度体系抗倒塌能力,采用了抗地震倒塌能力谱。(4)建立了2007年E-Defense三维足尺钢框架振动台模型；以3%应变作为BRB低周疲劳破坏准则,采用IDA方法比较了不同地震动强度下BRB框架及附加刚度BRB框架层间位移角分布情况,以DCF作为损伤分布控制的指标,说明了附加刚度有利于各层BRB充分耗能；通过比较不同次结构地震响应曲线,说明了附加刚度能有效控制楼层的最大位移角。
[Abstract]:Under earthquake action, the displacement angle between one layer of frame structure may be much larger than that of other floors, thus forming a weak layer, and the ability of resisting collapse of frame structure under the action of P- effect is reduced. In this paper, a new structure system, buckling Restrained Brace, BRB) frame with additional stiffness constraint, is proposed in this paper. The distribution uniformity of floor displacement angle can be controlled by additional stiffness under earthquake action. And the additional stiffness can be used as "fuse" for low cycle fatigue fracture of BRB. In this paper, the hysteretic characteristics of the BRB with additional stiffness are verified by the tests at the member level, the seismic behavior of the new system is analyzed by finite element simulation of the structure level, the main research work is as follows: 1) the components and working mechanism of the additional stiffness BRB are analyzed. A new type of lightweight and assembled BRB with additional stiffness is proposed. The BRB hysteretic curve of additional stiffness is obtained by quasi-static test of the members. The effects of inner and outer cylinder misalignment and bolt slip on the performance of the member are analyzed. Based on the double-fold elastic-plastic model, the equivalent viscous damping ratio of BRB, self-reset and additional stiffness BRB is compared. The simplified two-dimension bar system model based on opensees can simulate the hysteretic performance of BRB with additional stiffness better. According to the American seismic code, a 9-story braced hinged BRB frame and a BRB frame with additional stiffness are designed, which are based on material superposition and element superposition. The simplified modeling method of BRB with additional stiffness in the structure is proposed, and the elastic-plastic time-history analysis of the BRB frame and the BRB frame with additional stiffness in 20 seismic waves shows that the additional stiffness BRB can effectively control the uneven distribution of the displacement angle between the layers. In order to solve the problem of excessive acceleration and base shear force caused by additional stiffness, the supporting displacement corresponding to the median displacement angle between floors of BRB frame should be taken as the starting displacement of BRB frame with additional stiffness. It is suggested that the "fuse" device of friction damper should be used at the node to explain the theoretical basis of the equivalence of multi-degree-of-freedom system to single-degree-of-freedom system. The Ibarra-Krawinkler model is selected on the basis of comparing the characteristics of different models. The system of additional stiffness and single degree of freedom with P- effect is established by using the classical system of single degree of freedom. A method of searching the collapse point of incremental dynamic time history analysis based on "dichotomy" is proposed. The method is used to analyze the parameters of single-degree-of-freedom system with additional stiffness, and to compare the anti-collapse ability of single-degree-of-freedom system with additional stiffness in different periods. The shaking table model of E-Defense full-scale steel frame in 2007 is established by using the seismic collapse resistance spectrum. The 3% strain is used as the low cycle fatigue failure criterion of BRB. The distribution of displacement angle between BRB frame and BRB frame with additional stiffness under different ground motion intensity is compared by using IDA method. Taking DCF as the index of damage distribution control, it is shown that the additional stiffness is beneficial to the sufficient energy consumption of each floor BRB. By comparing the seismic response curves of different substructures, it is shown that the additional stiffness can effectively control the maximum displacement angle of the floor.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.11

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