黏滞阻尼器对摇摆钢框架结构抗震性能的影响分析

An Analysis of the Influence of Viscous Damper on the Seismic Performance of Rocking Steel Frame

放松结构与基础之间的约束,使结构在地震作用下可以发生摇摆,进而耗散地震能,减轻结构破坏程度,这类结构称之摇摆结构。文章结合最新的四水准抗震设防目标,即“小震及中震不坏;大震可更换、可修复;巨震不倒塌”,建立单榀三跨六层摇摆钢框架数值模型与传统固定支座钢框架数值模型,两者的区别在于摇摆钢框架在竖直方向用只受压不收拉的非线性弹簧连接,在水平方向和转角方向上,两者一样,并进行地震动对比分析,研究其抗震性能。结果表明虽然摇摆钢框架自身抗震性能优越,但是其层间位移角超过了限值。接着在摇摆钢框架中加入黏滞阻尼器进行耗能,研究其抗震性能。结果表明:其抗震性能进一步提高,并能满足四水准抗震指标。

Relaxing the restraint between the structure and the foundation allows the structure to swing under the action of an earthquake,thereby dissipating seismic energy and reducing the degree of structural damage.This type of structure is called a swing structure.According to the four-level seismic fortification target,which means that after a small earthquake or a medium earthquake,the structure remains good;after a great earthquake,the structural damages can be replaced and repaired and after a violent earthquake,the structure will not collapse,a numerical model of a single-three-span,six-story rocking steel frame and a numerical model of traditional fixed steel frame are established in this paper.The difference between the two is that the rocking steel frame is connected in the vertical direction by a non-linear spring that is only compressed and not pulled,and in the horizontal direction as well as in the corner direction,there is no difference.A comparative analysis of ground motion is conducted to study its seismic performance.The results show that although the rocking steel frame itself has superior seismic performance,the inter-layer displacement angle exceeds the limit.Then,a viscous damper is added to the swaying steel frame to dissipate energy and study its seismic performance.The results show that its seismic performance is further improved and it can meet the four-level seismic index.