摘要
改进能力谱法可以较好地评估结构抗震性能,在工程中得到了广泛的应用。本文在此基础上指出,由改进能力谱方法求得的延性是结构的延性需求,并不是结构的实际延性能力,不能以此代表结构在罕遇地震作用下的实际抗震能力。其次,基于弹塑性损伤反应谱(简称"RD谱"),结合模态Pushover分析,提出了基于RD谱的能力谱分析方法,通过RD谱分析所得的延性是结构的实际延性能力,从而可进行结构的抗震能力验算,并给出结构延性富余度的概念,即可明确结构经历某一级地震作用后体系所含的延性富余度。模态Pushover分析可有效地考虑结构高振型的影响,提高了结果的分析精度。最后,通过例题分析,说明了本文方法的方便性和可行性,文中分析结果反映了结构抗倒塌能力,通过与改进能力谱法的所得延性需求或位移需求进行比较,可求出结构体系所含的延性富余度。
Modified capacity spectra method（MCSM） can well access the performance of frame structures and is widely used in the actual engineering projects.The ductility of structure obtained by using MCSM is not the capacity of structure,but the demand.It can＇t stand for the actual seismic capacity of structure subjected to earthquake action.On the basis of inelastic damage spectra,denoted as ＂RD＂ spectra,a new CSM based on ＂RD＂ spectra is presented,called RCSM.The ductility obtained by using RCSM is the actual seismic capacity of structure,and can be considered to be ultimate ductility for collapse evaluation.Ductility redundancy index is then defined,i.e.the ductility redundancy of structure after its suffering certain level of earthquake action.Furthermore,modal pushover analysis is adopted to improve the precision of analysis,which can consider the high modal influence of buildings.Finally,the example shows the advocated method is feasible and convenient.The results obtained from RCSM reflect collapse-resistant capacity of building.Ductility redundancy indices can be achieved by comparing RCSM results to MCSM results after suffering certain level of earthquake action in the end.
出处
《地震工程与工程振动》
CSCD
北大核心
2011年第2期40-46,共7页
Earthquake Engineering and Engineering Dynamics
基金
国家重点基础研究发展(973)计划项目(2007CB714202)
关键词
非线性损伤谱
模态推覆分析
能力谱法
延性
inelastic damage spectra
modal pushover analysis
capacity spectra method
ductility
