基于含耗能梁段钢框筒侧向力分布的影响比较

含可更换剪切型耗能梁段钢框筒是一种新型消能减震结构,利用部分裙梁跨中耗能梁段集中塑性变形,方便震后快速替换和结构功能恢复。利用时程分析进行该结构截面的初选计算成本高,常用侧向力分布方式与时程分析的分析结果差异以及对该结构设计安全性的影响需要评估。利用SAP2000软件对1个30层含耗能梁段钢框筒进行了双向地震下的时程分析和五种侧向力分布方式的Pushover分析,并比较了"三水准"下的楼层位移、层间位移角、层剪力、层倾覆弯矩、性能点,以及大震下的柱轴力、塑性铰分布,并评价了各侧向力分布方式的影响和给出了该结构的一些设计建议。研究表明:各侧向力分布在含耗能梁段钢框筒的性能评估中有一定的参考价值,单一侧向力分布均不足以预估它的性能,宜考虑两种或多种侧向力分布来评估其性能;大震下各侧向力分布的最大层间位移角明显高于时程均值,各侧向力分布下结构的延性系数约为2;在含耗能梁段钢框筒的初步设计中,可根据均匀分布、SRSS分布、高度等效分布初选构件截面,最后宜采用时程分析对截面进行校核。

Comparison of influence of lateral load patterns on steel framed-tube structure with links

The steel framed-tube structure with replaceable shear links(SFTS-links)is a new structure with energy dissipation,which utilizes links located in mid-span of partial spandrel beams to centralize plastic deformation for the purpose of rapid replacement and recovery of structural function after earthquakes.Selecting sections of its members preliminarily by means of time history analysis will result in higher computational costs.The difference in analysis results from the common lateral load patterns and time history analysis and the influence of lateral load patterns on design safety of SFTS-links need to be evaluated.Time history analysis of bi-directional earthquakes and Pushover analysis of five lateral load patterns were conducted for a 30-storey SFTS-links by SAP2000 software,and floor displacements,storey drift angles,storey shear,storey overturning moment and performance points under three levels(frequent,moderate and rare earthquake)were compared,and axial force of columns,plastic hinge distribution under rare earthquakes were also compared.And the influence of lateral load patterns on structural performance was evaluated and several design suggestions on the SFTS-links were given.The results shows that calculation results of lateral load patterns have certain reference value in the behavior estimation of the SFTS-links.The single lateral load pattern is not enough to predict its performance,and two or more lateral load patterns should be considered to evaluate its behavior.The maximum storey drift angle by each lateral load pattern under severe earthquake is obviously larger than the average value by elasto-plastic time history,and ductility coefficient of the SFTSlinks under each lateral load pattern is about 2.Sections of components can be selected according to uniform distribution,SRSS distribution and height equivalent distribution in the preliminary design of SFTS-links,and finally,time history analysis should be used to check the estimated sections.