含可更换剪切型耗能梁段的高强钢框筒结构抗震性能分析

Analysis on the Seismic Performance of High-Strength Steel Framed-Tube Structure with Replaceable Shear Links

针对传统钢框筒结构地震耗能差和震后修复难度大等问题,结合剪切型耗能梁段耗能能力强及震后易修复、钢框筒抗侧刚度大、高强钢强度高且节约材料的优点,提出一种新型高层钢结构形式———含可更换剪切型耗能梁段的高强钢框筒结构(HSS-FTS)。给出了HSS-FTS的初步设计方法和耗能梁段的布置原则。为比较HSS-FTS和传统钢框筒结构(FTS)的抗震性能,采用SAP2000各建立了一个40层的HSS-FTS和FTS有限元模型,验证了有限元建模的合理性,分别对两个结构进行反应谱分析和动力弹塑性时程分析。结果表明:多遇地震下,HSS-FTS和FTS的层间位移角、基底剪力、楼层剪力和剪力滞后效应无显著差别,HSS-FTS可以满足抗震规范层间位移角的限值要求。罕遇地震和超大震作用下,HSS-FTS的柱轴力分布相比FTS更为均匀,减小了结构的剪力滞后效应,HSS-FTS的塑性铰主要集中在耗能梁段处,改变了FTS的塑性铰发展机制,具有理想的破坏模式。在罕遇地震和超大震作用下,HSS-FTS的层间位移角相比FTS分别降低了11.98%和13.63%,可有效减小震后结构的残余变形,降低耗能梁段的更换难度。HSS-FTS改变了FTS的耗能机制,在罕遇地震和超大震作用下,其耗能量相比FTS分别提高了86.58%和151.09%,其耗能能力显著提升,有效降低了结构的水平地震作用,可减轻除耗能梁段外的非耗能构件受损程度,此种新型高层钢结构形式更易于震后修复与功能的快速恢复。

A high-strength steel framed-tube structure(HSS-FTS)with replaceable shear links is designed to solve the poor seismic energy dissipation and repairable capacities of traditional steel framed-tube structure,which combines the advantages of shear link,framed-tube structure and high-strength steel.The preliminary design method of HSS-FTS and the layout principles of shear links are presented.Finite element models(FEMs)of one traditional 40-story framed tube structure(FTS)and one 40-story HSS-FTS are built by SAP2000.The elastic response spectra and elastic-plastic dynamic time-history analyses are performed to investigate their seismic performance.The analyses results indicate there are no significant differences for the performance between two FEMs under frequent earthquakes,including the inter-story drifts,base shear force,story shear force and shear lag effects.HSS-FTS could satisfy the requirements of inter-story drift limitation under frequent earthquakes.Under severe and mega earthquakes,the column axial force distribution of HSS-FTS was more uniform than that of FTS,which could effectively reduce the shear lag effects of structure.The plastic hinges and damage are generated at the beams and some columns of the FTS and the plastic deformation of the HSS-FTS mainly concentrated on the shear link segment,leading to an ideal failure mode.Under severe and mega earthquakes,the average maximum inter-story drift of the HSS-FTS are 11.98%and 13.63%lower than those in FTS,respectively.Moreover,the average dissipated energy of the HSS-FTS is 86.58%and 151.09%higher than those in FTS respectively under severe and mega earthquakes,which indicates the energy dissipation capacity of HSS-FTS is significantly improved.Therefore,HSS-FTS can reduce the effects of earthquakes,also for the damage of non-dissipative components.HSS-FTS can be apt to functional recovery after earthquakes.