带屈曲约束支撑的V型偏心支撑钢框架抗震性能研究

发布时间：2018-05-17 07:25

本文选题：V型偏心支撑 + 屈曲约束支撑　；参考：《西安科技大学》2017年硕士论文

【摘要】：偏心支撑钢框架通过耗能梁发生剪切变形来耗能,其侧向支撑不发生屈曲才能确保耗能梁发生剪切屈服。但在结构跨度和高度较大时,侧向支撑需要增加截面面积来满足自身稳定性能和轴压比的要求,这将导致结构自重和建造成本的增大。屈曲约束支撑在受拉和受压下不易发生屈曲且耗能效果好,因此用屈曲约束支撑代替偏心支撑钢框架的侧向支撑,具有一定的研究价值。本论文以带屈曲约束支撑的V型偏心支撑钢框架为研究对象,首先将模型进行简化,对其单自由度模型的等效阻尼和等效刚度进行计算,并分析其设计要点。建立普通V型偏心支撑钢框架(VEBF)和带屈曲约束支撑的V型偏心支撑钢框架(VEBF-B)分析模型,通过Push-over分析表明:屈曲约束支撑能够减缓框架柱塑性铰的发展速度,对框架柱进行了保护,有利于实现抗震设防“强柱弱梁”的目标。其次本论文通过对比VEBF-B框架和VEBF框架的时程分析,多遇地震作用下,得到VEBF-B框架的顶点侧移、基底剪力和顶点加速度都要比VEBF框架较小,但相差不是很明显。主要原因是大多数屈曲约束支撑在多遇地震作用下并没有发生屈服,其作用和普通支撑基本一样,只是增加结构的抗侧刚度。罕遇地震作用下,VEBF-B框架和VEBF框架的抗震性能具有很大的差异,VEBF-B框架的顶点侧移、基底剪力和顶点加速度都得到明显减少。主要原因是VEBF-B框架中大量的屈曲约束支撑发生了屈服,其耗能优势使得整个结构变得更合理。VEBF-B框架的基底剪力得到有效的减少,不仅有利于提高结构的抗震性能,还对降低结构造价具有很大的优势。最后本论文从基于能量平衡原理对结构进行能量分析,结果表明:在VEBF-B框架中加设屈曲约束支撑,有利于减轻地震作用对主体结构的损伤,屈曲约束支撑耗散大部分地震能量;地震作用下输入到结构中的能量越多,屈曲约束支撑耗散能量的比例越大。研究VEBF-B框架的抗震性能,对进一步优化结构的抗震设计和建筑物的经济性能具有一定的理论意义和实用价值。
[Abstract]:Eccentrically braced steel frame dissipates energy through shear deformation of energy dissipation beam, and the lateral bracing does not buckle in order to ensure shear yield of energy dissipation beam. However, when the span and height of the structure are large, the lateral bracing needs to increase the cross-section area to meet the requirements of its own stability performance and axial compression ratio, which will lead to the increase of structural weight and construction cost. Buckling restrained braces are not easy to buckle under tension and compression and the energy dissipation effect is good. Therefore, it is valuable to study the lateral braces of eccentric braced steel frames by buckling restrained braces instead of eccentrically braced steel frames. In this paper, the V-shaped eccentrically braced steel frame with buckling constraints is taken as the research object. Firstly, the model is simplified, the equivalent damping and stiffness of the single-degree-of-freedom model are calculated, and the key points of its design are analyzed. The analysis models of common V-type eccentrically braced steel frame (VEBF) and V-type eccentrically braced steel frame (VEBF-B) with buckling constraint braces are established. The Push-over analysis shows that buckling restrained braces can slow down the development of plastic hinges of frame columns. The frame column is protected, which is propitious to achieve the goal of seismic fortification of "strong column and weak beam". Secondly, by comparing the time history analysis of VEBF-B frame and VEBF frame, it is found that the peak of VEBF-B frame moves sideways and the base shear force and peak acceleration are smaller than that of VEBF frame, but the difference is not obvious. The main reason is that most buckling restrained braces do not yield under the frequent earthquake. The effect of buckling restrained braces is basically the same as that of common braces and only increases the lateral stiffness of the structures. The seismic behavior of VEBF-B frame and VEBF frame under rare earthquake is very different. The vertex of VEBF-B frame is shifted sideways and the base shear force and the acceleration of vertex are obviously reduced. The main reason is that a large number of buckling restrained braces in VEBF-B frame yield, and the advantages of energy dissipation make the whole structure become more reasonable. VEBF-B frame base shear force is effectively reduced, which is not only conducive to improving the seismic performance of the structure. It also has a great advantage in reducing the cost of structure. Finally, the energy analysis of the structure based on the principle of energy balance is carried out. The results show that the addition of buckling constraint braces in the VEBF-B frame is helpful to reduce the damage caused by earthquake to the main structure, and the buckling constraint bracing dissipates most of the seismic energy. The more energy input into the structure under seismic action, the larger the proportion of dissipative energy of buckling restrained braces. The study of seismic performance of VEBF-B frame has certain theoretical significance and practical value for further optimization of seismic design of structures and economic performance of buildings.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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