李国强  谢卫兵  沈祖炎
  （同济大学 上海 200092）

[提要]  本文首先将高层支撑钢框架结构分解成纯框架和纯支撑体系两部分，并与一列受载铰接刚性杆并联，以考虑几何非线性的影响；然后将框架部分简化为半刚架，将支撑体系部分简化为铰接桁架，以此进行结构弹塑性地震反应分析。在前人试验和理论研究成果的基础上，本文还提出了能准确反映钢支撑主要滞回特征的支撑恢复力模型，便于工程实用。通过算例对比分析，表明采用本文提出的高层支撑钢框架简化模型进行弹塑性地震反应分析，具有计算精度高、计算自由度少、计算时间省的优点，是一种有效的近似方法。
[关键词]  高层结构 支撑钢框架 弹塑性 地震反应 简化模型

Regarding a tall braced steel frame as a frame plus a bracing system, the analysis of the structure can be simpiified. The frame part of a braced frame can be simplified as a half - frame with only one column each storey, and the bracing part of the braced frame can be treated as a hinged vertical truss. For the analysis of elasto - plastic response of braced steel frames subjected to earthquakes, a practical restoring force model is proposed. It is shown by numerical investigation that the simplified model presented in this paper is effective for predicing the elasto - plastic seismic response of tall braced steel frames.
Keywords: tall building structure; braced steel frame; elasto - plasticity; seismic response