两种不同需求曲线的能力谱评价方法比较  

Comparison of capacity spectrum methods with two different demand curves

作　　者：梁仁杰[1] 吴京[1,2] 孟少平[1,2] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2009年第S2期169-173,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50878055);江苏省自然科学基金资助项目(BK2008313)

摘　　要：在计算能力谱方法需求曲线时,考虑了基于结构等效阻尼比和R--μT关系2种对弹性反应谱的折减方式,并对结构进行非线性时程分析作为比较依据.结果表明,采用能力谱评价方法对多层结构进行抗震能力分析是可行的,在弹性范围,2种折减方式所得结果基本一致,进入塑性后,有较大差别.传统能力谱法考虑等效阻尼比低估了结构的变形,有较大误差,主要原因是等效阻尼比的计算假设和实际阻尼表现不符,由于R-μ-T关系的改进能力谱法和时程分析结果基本吻合,在对结构进行抗震能力评价时,采用考虑R--μT关系的改进方法可有效地提高精度,满足工程需要.When the demand curve is established in the capacity spectrum method,two ways are considered to reduce the elastic response spectrum;one is based on the structural equivalent damping ratio and the other is based on the R-μ-T relationship.Then the results are compared with those of non-linear time history analysis.The results show that the capacity spectrum method is feasible to analyze the seismic capacity of multi-story structures.The two results are almost the same in the elastic rang;but in the plastic rang,there are large differences between them.The traditional capacity spectrum method which considers the equivalent damping ratio underestimates the deformation of a structure.This causes a large error because the calculation assumption of the equivalent damping ratio is not consistent with the actual damping under earthquake.However,the results of the improved capacity spectrum method which considers the R-μ-T relationship are basically the same as those of time history analysis.When the seismic capacity of a structure is estimated,the improved method which considers the R-μ-T relationship can effectively improve the precision and meet the engineering demands.

关 键 词：能力谱方法 等效阻尼比 R--μT关系 弹塑性需求曲线 

分 类 号：P315.9[天文地球—地震学]