基于剪力比的黏弹性阻尼腋撑-RC框架结构设计方法

现有减震设计方法需进行繁琐的迭代，其效率有待提高。基于剪力比的概念，采用黏弹性阻尼腋撑，设置罕遇地震下腋撑与框架结构的耗能比，提出了基于剪力比的黏弹性阻尼腋撑-RC框架结构抗震设计方法。选取7条地震动记录，根据不同剪力比 α 对6层、9层、12层模型设置不同参数的腋撑，进行罕遇地震下弹塑性动力时程分析。研究了腋撑耗能占地震输入结构总能量的关系，并将各模型最大层间位移角与GB 50011—2010《建筑抗震设计规范》的规定值进行了对比。从层间位移角、层剪力、顶层最大位移值、顶层峰值加速度等方面比较了结构的减震效果。研究结果表明：对于高40m以下的框架结构，耗能比为0.6时，剪力比 α 的合理取值范围在0.10~0.20之间；剪力比α取0.15时，RC框架结构的最大层间位移角、顶层最大位移值均减少34%~45%，层剪力、顶层加速度峰值均减少19%~23%。

Seismic design method of RC frame structure with knee brace of viscoelastic damper based on shear ratio

Considering the cumbersome status of existing design methods and the proportion of the energy consumption in the knee brace under rare earthquakes, the seismic design method of RC frame structure with knee brace of viscoelastic damper based on shear ratio is proposed. Firstly, seven ground motion records are selected. Then, knee braces with different parameters of three models including six stories, nine stories and 12 stories, are set up for every model according to different shear ratios. The elasto-plastic dynamic time history analyses are taken. Secondly, the ratio of the energy dissipated by the knee braces to the total energy input into the RC frame structure is studied. And the maximum inter-story displacement angle of every model is compared with the code. Finally, the damping effect of the structure is analyzed from four aspects: the inter-story displacement angle, the story shear force, the maximum displacement of the roof and the peak value of the roof acceleration. The results of the study show that the reasonable range of shear ratio is from 0.1 to 0.2 for structures below 40m when the energy consumption ratio is 0.6. The maximum inter-story displacement angle and the maximum displacement of the roof of the RC frame structure are both reduced by 34%-45%, the story shear and the peak acceleration of the roof are both reduced by 19%-23% when the shear ratio is 0.15.