多层屈曲约束支撑钢框架动力响应机理分析

Dynamic response mechanism analysis of multi-story buckling-restrained braced steel frame

为了研究多层屈曲约束支撑钢框架(BRBF)动力响应机理,采用国际上最常见的BRBF结构形式为研究对象,以屈曲约束支撑BRB水平力分担率β为主要研究参数,进行弹塑性动力二阶非线性分析,探讨了层损伤分布机理以及构件持有性能。结果表明:不同地震波的弹性体系能量谱曲线和结构基本周期对应关系影响多层BRBF结构的最大层间位移反应值和BRB的层最大延性比值;地震波加速度时程的随机性对多层BRBF结构动力损伤分布影响明显,尤其多层BRBF结构抗震设计时有必要考虑地震动瞬时能量影响;BRB对结构减震效果明显,随着BRB水平力分担率β值的增加,BRB最大延性比以及最大累积塑性延性比有相应减小的趋势。

To study the dynamic response mechanism of multi-story buckling-restrained braced steel frame（ BRBF）,the most commonly used BRBF structural type was adopted as study object and average horizontal force sharing ratio β of buckling-restrained brace（ BRB） was taken as the main study parameter to carry out second-order nonlinear elasticplastic dynamic analysis to explore the story damage distribution mechanisms and the structural member performances.The research results are as follows.The corresponding relations between elastic system energy spectrum of different earthquake waves and structural fundamental period effect maximum inter-story drift response value of multi-story BRBF and maximum story ductility ratio of BRB.The randomness of seismic acceleration time-history response affects obviously the structural dynamic damage distribution of multi-story BRBF,so it＇ s particularly necessary to consider the seismic instantaneous energy response on the multi-layer BRBF in the seismic design.BRB damping effect on the structure is obvious,and with the increasing of β value,BRB maximum story ductility ratio and maximum accumulated story ductility ratio have a decreasing trend.