考虑P-Δ效应和自适应模态侧力分布的结构抗震能力评估  

Evaluation of seismic capacity of structures considering P-Δ effects and adaptive modal lateral load distribution

作　　者：李刚[1] 江义[1] 

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116024

出　　处：《大连理工大学学报》2013年第1期4-11,共8页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(90815023,51021140006)

摘　　要：针对3种典型结构抗震能力表征,即传统的Pushover曲线、基于能量的Pushover曲线和能量能力曲线,详细地考察了自适应模态侧力分布加载方式与P-Δ效应对结构抗震能力评估的影响;对9层与20层钢框架结构进行了数值分析,结果表明:基于能量的Pushover曲线比传统的Pushover曲线表现出更光滑的双线性,且能够有效地避免传统高阶模态Pushover曲线可能失效的问题,能量能力曲线能够在基于能量的评估中得到合理的应用;自适应加载方式比不变的加载方式得到的结构屈服后承载能力要高,高阶模态时更为明显;考虑P-Δ效应比不考虑P-Δ效应得到的结构抗震能力要低,但是对中低层结构影响则很小.Three typical representations of seismic capacity of structures, including conventional Pushover curve, energy-based Pushover curve and energy-based energy capacity curve are shown, and P-△ effects and adaptive modal lateral load distribution on evaluating of seismic capacity of structures in detail are investigated. Then, numerical evaluation is implemented on 9-story and 20-story prototype steel moment resisting frame structures, and experimental results show： The energy-based Pushover curve behaves more smoothly bilinear than conventional Pushover curve, and can prevent the reversal of the higher modal conventional Pushover curve efficiently. The energy-based energy capacity curve can be applied to the energy-based evaluation rationally. The adaptive modal lateral load distribution produces larger capacity of the yielded structures than the invariant modal lateral load distribution, especially under the higher modal lateral load distributions. The structural seismic capacity considering the real existing P-△ effects is lower than that without considering P-△ effects, but for lower-and medium-story structures P-△ effects are unobvious.

关 键 词：结构抗震能力评估 PUSHOVER分析 P-Δ效应 自适应的模态侧力分布 不变的模态侧力分布 

分 类 号：P315.9[天文地球—地震学]