某周期比超限偏心结构地震反应控制分析

Earthquake response and control analysis of an eccentric structure with dampers

本文以周期比超限的某偏心结构工程为研究背景,基于SAP2000建立三维有限元模型,采用黏滞阻尼器、黏弹性阻尼器、软钢阻尼器、复合铅黏弹性阻尼器和钢支撑五种减震方案对其进行扭转控制,针对不同扭转控制方案分别进行了模态分析、反应谱分析和动力时程分析,对比研究了多遇地震作用下各控制方案的周期比、层间位移、支撑内力及阻尼器的耗能能力。研究表明:五种控制方案均具有有效抑制结构扭转振动响应的能力,降低结构的最大层间位移角,并使之满足规范要求;后四种控制方案能明显减小结构的周期比,将结构第一扭转反应控制在第三振型;对于此类偏心结构体系的扭转振动控制,本文建议阻尼器设置应尽量远离刚度中心,以达到最佳扭转控制效果。

An eccentric structure was selected as an example in this paper. Three-dimensional finite element model was constructed by using SAP2000. According to the natural characteristics of the building, five kinds of damping control plans of added viscous dampers, viscoelastic damper, metal damper, lead - viscoelastic dampers and steel braces were put forward to restrain the torsional response. In order to research period ratio, inter-story displacement, brace inner-force and energy dissipation behavior of dampers for the five control plans, this paper studies model analysis, response spectrum analysis and history analysis. The results show that all of the five control plans have behavior of restraining torsional response and reducing the max inter-story displacement greatly. The last four control plans can reduce the period ratio effectively and control the torsional response almost completely for the first model. In order to achieve the optimal torsional-control effect for this eccentric structure, this paper suggests that dampers should be installed away from the rigidity center.