屈曲约束支撑结构的受力性能研究

发布时间：2018-05-29 19:24

本文选题：屈曲约束支撑 + 有限元分析　；参考：《西安科技大学》2015年硕士论文

【摘要】：框架支撑体系一直是高层结构常用的结构形式之一,但是传统支撑容易发生屈曲失稳,为了保证支撑的整体稳定,只能在设计上增大截面尺寸,控制长细比。而支撑过强往往会导致主体结构构件(梁、柱)的相对较弱,当遭遇罕遇地震时,对主体结构的抗震非常不利。随着耗能减震技术的发展,屈曲约束支撑的出现解决了这一难题,屈曲约束支撑既能保证支撑只发生屈服而不屈曲失稳,又能保证支撑先于主体结构进入屈服状态,通过自身屈服后的良好滞回性能,消耗大部分地震输入的能量,进而可以大幅度减轻主体结构遭受罕遇地震的破坏程度。本文在理论推导的基础上,利用ANSYS有限元软件对屈曲约束支撑模型进行特征值屈曲分析和模态分析,并与欧拉理论比较确认模型的准确性。在模态分析的基础上,考虑初始缺陷的情况下对4个系列的屈曲约束支撑进行了极限承载力的分析,对影响屈曲约束支撑承载力的因素进行了比较全面的研究,并得到其的合理取值范围:约束刚度比2.0~3.0、芯材宽厚比5~15、约束间隙1~2mm、初始缺陷5/1000以内。最后运用结构分析软件SAP2000对屈曲约束支撑钢框架结构与普通支撑钢框架结构的某工程实例进行动力时程对比分析,分析表明在多遇地震作用下,屈曲约束支撑钢框架与普通支撑钢框架表现相近,说明在正常使用情况及小震时屈曲约束支撑与普通支撑区别不大;在罕遇地震作用下,屈曲约束支撑钢框架的各项指标均比普通支撑钢框架表现优良,说明在较大地震时,屈曲约束支撑最先进入屈服,耗散了大量的地震能量,减小主体结构受到地震作用的动力响应,从而起来到很好的减震耗能效果。本文全面深入地分析了屈曲约束支撑受力性能及其影响因素,同时对屈曲约束支撑钢框架结构与普通支撑钢框架结构进行了对比分析,研究工作和得出的结论对于指导工程实践具有重要的参考价值,为进一步研究屈曲约束支撑结构的抗震性能打下了良好的基础。
[Abstract]:Frame bracing system has always been one of the commonly used structural forms of high-rise structures, but the traditional braces are prone to buckling instability. In order to ensure the overall stability of the braces, the design can only increase the cross-section size and control the aspect ratio. Too strong bracing often leads to the relative weakness of the main structural members (beams and columns). When the earthquake occurs rarely, it is very unfavorable to the earthquake resistance of the main structure. With the development of energy dissipation technology, the emergence of buckling restrained braces solves this problem. Buckling restrained braces can not only guarantee the buckling of the braces but not buckle instability, but also ensure that the braces can enter the yield state before the main structure. Through the good hysteretic performance after self-yielding, the energy input from most earthquakes can be consumed, and the damage degree of the main structure subjected to rare earthquakes can be greatly reduced. On the basis of theoretical derivation, the eigenvalue buckling analysis and modal analysis of buckle-constrained bracing model are carried out by using ANSYS finite element software, and the accuracy of the model is confirmed by comparing with Euler's theory. On the basis of modal analysis, the ultimate bearing capacity of four series buckling braces is analyzed considering the initial defects, and the factors affecting the buckling restrained braces are studied comprehensively. The reasonable value range is obtained as follows: the ratio of restraint stiffness is 2.0 ~ 3.0, the ratio of core width to thickness is 5 ~ 15, the gap is 1 ~ 2 mm, and the initial defect is less than 5 / 1000. Finally, the dynamic time-history comparison between buckle-constrained braced steel frame structure and common braced steel frame structure is carried out by using structural analysis software SAP2000. The behavior of buckling restrained braced steel frame is similar to that of common braced steel frame, which indicates that buckling restrained bracing is not different from common bracing in normal use and small earthquake. Each index of buckle-constrained braced steel frame is better than that of common braced steel frame, which shows that buckling restrained bracing leads to yield first and dissipates a great deal of seismic energy during large earthquake. The dynamic response of the main structure subjected to earthquake is reduced, so that the energy dissipation effect of the main structure is very good. In this paper, the mechanical behavior of buckle-restrained braces and its influencing factors are thoroughly analyzed, and the comparison between buckle-constrained braced steel frame structures and common braced steel frame structures is carried out. The research work and conclusions have important reference value for guiding engineering practice and lay a good foundation for further study on seismic behavior of buckled braced structures.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.11

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