This study looks at the influence of plan-asymmetric properties on seismic performance of steel framed buildings by means of a comparative study. The seismic fragility curves of a symmetrical nine-story steel framed building and three asymmetric-plan buildings, which are the variations of the mentioned symmetrical building, are constructed through incremental dynamic analysis (IDA). The three asymmetric-plan buildings are torsionally stiff (TS), torsionally similarly stiff (TSS), and torsionally flexible (TF) buildings, respectively. The considered plan-asymmetric properties are eccentricity ratio and uncoupled frequency ratio. A comparative study of three damage states (DS) including immediate occupancy (IO), collapse prevention (CP), and global instability (GI) of the four buildings is conducted. The results show that in terms of slight damage, both the symmetrical building and the TSS building perform better. In terms of severe damage and collapse, the symmetrical building obviously outperforms the other three asymmetric-plan buildings. In addition, the TF building always performs the worst regardless of the DSs.

中文翻译：

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不同平面不对称特性钢框架结构抗震性能比较研究

本研究通过对比研究探讨了平面非对称特性对钢框架建筑抗震性能的影响。通过增量动力分析（IDA）构建了对称的九层钢框架建筑和三个非对称平面建筑的地震脆弱性曲线，它们是上述对称建筑的变体。这三个非对称平面建筑分别是扭转刚性（TS）、扭转相似刚性（TSS）和扭转柔性（TF）建筑。所考虑的平面非对称特性是偏心比和非耦合频率比。对四栋建筑物的立即占用（IO）、防倒塌（CP）和全局不稳定（GI）三种损坏状态（DS）进行了比较研究。结果表明，在轻微损伤方面，对称建筑和TSS建筑都表现更好。在严重破坏和倒塌方面，对称建筑明显优于其他三座非对称平面建筑。此外，无论 DS 是什么，TF 构建总是表现最差。