【作者】 陶湛湛；

【导师】 王社良；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2010， 硕士

【摘要】 高层钢框架结构一般情况下抗侧刚度较小,在水平荷载作用下的水平位移较大。这样,若在这类结构的框架柱之间增设普通钢支撑,不仅能够有效地提高结构的抗侧刚度,而且也能提高结构的抗震承载力。但是,普通钢支撑存在着受压时容易屈曲等问题,直接影响着整体结构的抗震性能。因此,为了克服普通钢支撑存在的容易屈曲等不足,在工程中可采用屈曲约束支撑来替代普通钢支撑。经过合理设计,屈曲约束支撑能够在罕遇地震下率先屈服,以保护主体结构不发生破坏,从而保证整体结构的抗震性能。本文首先探讨了屈曲约束支撑的相关理论分析和计算模型,然后采用MIDAs软件,对纯框架结构、普通支撑框架结构、屈曲约束支撑框架结构进行了计算机建模和抗震性能分析,比较了三类框架结构在多遇地震和罕遇地震作用下的主要地震反应特征。结果表明,多遇地震下屈曲约束支撑与普通支撑性能近似,均能够有效地减小结构的水平位移,但在罕遇地震下,屈曲约束支撑表现出很大的优越性,能够耗散大部分地震能量,大大减小结构层间侧移和梁柱构件内力。论文还探讨了屈曲约束支撑框架结构基于位移的抗震设计方法,即以多遇地震下纯框架结构的层间侧移为设计依据,根据目标层间位移确定屈曲约束支撑的面积和数量,再以罕遇地震下结构的能量为条件,验算所设置的屈曲约束支撑能否满足要求。Pushover分析结果表明,屈曲约束支撑框架结构能够较好的满足抗震性能和经济性的要求。此外,论文还对6种不同布置方式的屈曲约束支撑钢框架结构进行了MIDAS建模和相应的抗震性能分析,比较了罕遇地震下各方案的主要地震反应特征,并根据投资-效益准则对结构进行了费用评估,综合考虑性能和造价等因素,选择了最优布置方案,为工程应用提供了理论依据。更多还原

【Abstract】 The displacement of high-rise steel frame is large under horizontal action for the flexibility, if braces are fixed, the stiffness and seismic behavior of frame are improved, however, conventional brace tends to buckling under compression, so it’s better to replace conventional brace with buckling-restrained brace(BRB) which yields at whole cross section for the effect of constraint element. Rational designed buckling-restrained brace was the first to yield under sereve earthquake and the main structure was protected.Basic theory of mechanics of buckling-restrained brace was first introduced. Modeling and analysis of frame, conventional brace frame and buckling-restrained brace frame were realized by finite element software MIDAS, by comparing three types of frame, structure reaction under earthquake was obtained. The behavior of conventional brace and buckling-restrained brace are similar under frequent earthquake, frame with conventional brace or buckling-restrained brace tends to much smaller displacement than simple frame; the seismic behavior of buckling-restrained brace is much better than conventional brace under sereve earthquake, a good seismic reduction effect of buckling-restrained brace frame was gotton.Displacement-based seismic design for buckling-restrained brace frame was discussed, based on storey drift of simple frame under frequent earthquake and target displacement, the area and quantity of buckling-restrained brace were determined, then the designed buckling-restrained braces were calculated on account of energy structure absorbed under sereve earthquake. Pushover analysis showed that a good seismic performance and economy were obtained by means of method refered. 6 types of buckling-restrained brace frame models were analyzed by software MIDAS and seismic response under sereve earthquake were compared; besides, the cost of structure was estimated based on cost-benefit rules, and the optimization type of buckling-restrained brace frame was gotten after overall considersion.更多还原