Nonlinear static procedures are commonly used to compute seismic demands of structural systems. This paper combines the modified capacity spectrum method (MCSM) and modal pushover analysis (MPA) and proposes a new nonlinear static method called MPA–MCSM. To evaluate the accuracy of the proposed method, 30 different buckling-restrained braced (BRB) structures which consist of 3-, 9- and 20-story BRB frames with irregularities in plan and in elevation are selected. Each structure was analyzed subjected to seven pairs of ground motions. As a measure for the performance assessment of the proposed method, four structural seismic demands: (1) peak roof displacement, (2) story drift, (3) story shear and (4) base shear, are computed for each considered structure. The accuracy of MPA–MCSM responses is checked against the results obtained from nonlinear time-history analysis (NL-THA). The results reveal that MPA–MCSM provides conservative seismic demands for BRB frames.

中文翻译：

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用于估计非线性不规则 BRB 框架抗震需求的新 NSP 的性能评估

非线性静态程序通常用于计算结构系统的抗震要求。本文结合了改进的容量谱方法 (MCSM) 和模态推覆分析 (MPA)，提出了一种新的非线性静态方法，称为 MPA-MCSM。为了评估所提出方法的准确性，选择了 30 种不同的屈曲约束支撑 (BRB) 结构，这些结构由平面和立面不规则的 3、9 和 20 层 BRB 框架组成。每个结构都经过七对地面运动的分析。作为所提出方法的性能评估的衡量标准，为每个考虑的结构计算四个结构抗震要求：(1) 峰值屋顶位移，(2) 楼层漂移，(3) 楼层剪切和 (4) 基础剪切。MPA-MCSM 响应的准确性根据非线性时程分析 (NL-THA) 获得的结果进行检查。结果表明，MPA-MCSM 为 BRB 框架提供了保守的抗震要求。