消能摇摆墙-框架结构的易损性研究

Seismic fragility study on rocking-wall-frame system with dampers

消能摇摆墙-框架结构由主体框架结构、摇摆墙、阻尼器和刚性连杆4部分组成。摇摆墙可以控制结构整体变形模式和塑性耗能的分布,抑制薄弱层产生。位移型阻尼器可以增加结构刚度,消耗地震输入能量,并将塑性损伤限定于局部区域,便于震后修复或更换。采用OpenSEES分别建立了纯框架结构、附加摇摆墙框架结构、附加摇摆墙和阻尼器框架结构的有限元模型,从ATC-63推荐的地震动记录集中选取20条地震波作为输入激励,对3种结构分别进行增量动力时程分析。以最大层间位移角作为易损性分析指标,评估了3种结构的抗震性能与抗倒塌能力。研究表明,消能摇摆墙-框架结构的抗震性能和抗倒塌性能最优,纯框架结构最差。通过分析地震动强度指标与结构峰值响应的相关性,验证了以地震动峰值加速度作为增量动力时程分析调幅指标的合理性。

Structures with rocking wall and dampers consists of main frame,rocking wall,dampers and connecting components.The additional rocking wall has the advantages of controlling deformation mode and preventing weak story.Displacement-based dampers can decrease seismic response,provide extra stiffness and limit plastic damage into certain region,for the convenience of replacement after-shock.OpenSEES is used to established three kinds of finite element models,representing frame,frame with rocking wall,frame with rocking wall and dampers,respectly.Twenty waves are chosen from the set recommended by ATC-63 and incremental dynamic analysis is conducted on theses models.Peak ground-motion acceleration is chosen as the index for adjusting waves’amplitude.Evaluation of seismic behavior and collapse performance is obtained by analyzing peak story drift.According to this study,rocking frame system with dampers has the most excellent seismic behavior and collapse performance among these models and frame structure is the worst.It’s reasonable to choose peak ground-motion acceleration as intensity measure,by the comparison of correlation between peak story drift and different intensity measures.