基于能量平衡的偏心结构多模态Pushover近似方法  

An approximate method of multi-mode Pushover analysis based on energy balance for plan-asymmetric structures

作　　者：王梦晨[1] 李刚[1] 曾岩[1] 江义 

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116023 [2]中交第三航务工程勘察设计院有限公司,上海200032

出　　处：《建筑结构学报》2016年第9期43-52,共10页Journal of Building Structures

基　　金：国家自然科学基金重大研究计划集成项目(91315301)

摘　　要：为了简化基于能量平衡的推覆分析,考虑高阶模态影响同时提高计算效率,提出了组合法和包络法。组合法采用将推覆分析解与高阶弹性解模态组合的方式,而包络法则将推覆分析解与整体弹性解进行包络处理。选取典型地震动,对9层和20层平面偏心结构进行响应分析,并与非线性时程分析、仅考虑基本模态的基于能量平衡推覆分析结果进行比较。结果表明:组合法和包络法能较好考虑高阶模态的影响,对扭转刚性、扭转柔性结构模型,组合法和包络法对质心处的位移响应预测较好,包络法在刚性边界处的位移响应预测较准而组合法在柔性边界处的位移响应预测较准,组合法对底层位移响应的预测普遍高于包络法,两方法对9层结构的响应预测比20层更准确。To simplify the algorithm of multi-mode Pushover analysis based on energy balance, two modified methods were proposed to take into account the higher mode effects and calculation efficiency. One was the combination method in which solution of Pushover analysis and higher-order elastic solutions were combined in modal analysis. The other was the envelope method in which the envelope of Pushover response and all the elastic responses from modal analysis was considered. Responses of 9-story and 20-story plan-asymmetric frame structures under typical earthquake loads were calculated by using these two methods separately. Comparisons were completed among the results of nonlinear time history analysis, Pushover analysis based on energy balance with basic mode only and the modified methods proposed here. It is shown that the higher mode effects on seismic response are estimated well by using the proposed methods. Both combination method and envelope method can get a reasonable prediction of responses at mass centers of torsionally-stiff and torsionally-flexible models, and the envelope method predicts the response of the stiff boundary better while the combination method predicts the response of the flexible boundary better. It is also found that the underlying response of combination method is generally higher than response of envelope method. Both of the two methods can get a better prediction of responses of 9-story structure than that of 20-story structure.

关 键 词：PUSHOVER分析 高阶模态 能量平衡 非线性分析 平面偏心结构 地震响应 

分 类 号：TU391.01[建筑科学—结构工程]