Y形高强钢组合偏心支撑框架结构弹塑性层剪力分布研究

Elasto-plastic story shear distribution of Y-type high strength steel composite eccentrically braced frame

为研究Y形高强钢组合偏心支撑框架结构(Y-HSS-EBF)的弹塑性层剪力分布,设计了4个不同层数且具有理想整体屈服模式的Y-HSS-EBF结构,同时建立了Y-HSS-EBF结构振动台试验试件的有限元模型并进行了验证,在此基础上考虑了结构层数、近场地震的速度脉冲效应以及远场地震加速度累积循环效应的影响,通过非线性时程分析获得了Y-HSS-EBF结构在罕遇水准近场、远场地震下层剪力分布,基于GB 50011—2010《建筑抗震设计规范》的底部剪力法提出了Y-HSS-EBF结构弹塑性层剪力分布模式,并与现有层剪力分布模式进行了对比。结果表明:近场地震波的速度脉冲效应以及远场地震波的加速度循环效应对Y-HSS-EBF结构的层剪力分布影响较大,应考虑其对结构层剪力分布的影响;建议的层剪力分布模式与时程分析结果的误差最小,在精度上优于文中其他层剪力分布模式,可以为Y-HSS-EBF结构基于性能的设计方法提供参考。

In order to investigate the elasto-plastic story shear distribution of Y-type high strength steel composite eccentrically braced frame （Y-HSS-EBF） , four Y-HSS-EBF models with different stories and global yield mechanism were established. Meanwhile, the finite element model of shaking table test specimen of Y-HSS-EBF was established and verified. The effects of story number, velocity pulse of near-fault motions and acceleration cumulative effect of far- fault motions were considered. Nonlinear time history analyses were conducted to obtain the story shear distribution of the structures during rare near-fault and far-fault earthquakes. The formula for calculating the elasto-plastic story shear distribution of Y-HSS-EBF was proposed based on equivalent base shear method in design code GB 500l[--20[0 ＇Code for seismic design of buildings＇ , and compared with other story shear distribution. Results indicate that the near-fauh earthquakes with velocity pulse and far-fault earthquakes with acceleration cumulative effect have different effects on the story shear distribution of structures. The story shear distribution proposed in this paper is more accurate than other ones, and can be adopted for the performance-based plastic design method of Y-HSS-EBF.