摇摆架减震框架结构静力弹塑性分析

Pushover analysis of frame structure with rocking frame

摇摆架减震框架结构是在原RC框架结构上增设轻型摇摆钢架而成。依据我国抗震规范设计了一栋抗震设防烈度为8度的6层RC框架结构及轻型摇摆钢架,对摇摆架减震框架结构的抗震性能进行了研究。利用Open Sees软件建立RC框架以及轻型摇摆钢架有限元模型,并对该模型进行静力弹塑性分析,分别从荷载-位移曲线、能力谱、性能点和层间位移角四个角度分析了摇摆架减震框架结构的抗震能力。结果表明:摇摆架能够有效分担原结构的基底剪力,在相同的顶点位移下,使原结构的承载力提高37%左右;增设摇摆架对原结构弹性状态下的刚度及周期影响较小,而当结构进入塑性阶段后,该摇摆架可以增加结构刚度并降低结构响应;在7度和8度罕遇地震作用下,原结构产生较大的层间位移角并且出现层屈服机制,利用摇摆架后不仅能够降低结构的响应,而且可以使结构保持在整体屈服机制下。

Frame structure with rocking frame consists of the initial RC frame structure with additional light-weight rocking steel frame. A 6-story RC frame structure installed with the light-weight rocking steel frame in area of 8 degree seismic fortification intensity was designed in accordance with the seismic design codes. The seismic behavior of the energy-dissipated frame structure with rocking frame was studied. The finite element models of RC frame structure and light-weight rocking steel frame were established by Open Sees software,and Pushover analysis was conducted. The seismic capacity of the energy-dissipated frame structure with rocking frame was analyzed in four perspectives of load-displacement curve,capacity spectrum,performance point and inter-story drift angle. The results show that rocking frame can effectively share base shear of the initial frame and improve the bearing capacity of the initial frame by about 37% under the same top displacement. Rocking frame has little effect on stiffness and period of the initial structure in elastic state and it can enhance the structure stiffness and decrease structural responses of initial frame when entering the plastic state. Rocking frame can decrease the structural responses and can also control the overall yielding mechanism as the yielding mechanism of the structure,considering the fact that initial structure has large inter-story drift angles and occurrence of layer yielding mechanism under the 7 degree and 8 degree rare earthquake actions.