考虑阻尼影响的新型周期性基础性能研究  

Research on performance of a novel periodic foundation considering damping effects

作　　者：孙飞飞[1,2] 刘越 戴晓欣[2] 肖蕾 Sun Feifei;Liu Yue;Dai Xiaoxin;Xiao Lei(State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学土木工程学院,上海200092

出　　处：《土木工程学报》2021年第7期1-11,42,共12页China Civil Engineering Journal

基　　金：国家自然科学基金(51778488)。

摘　　要：周期性结构独特的带隙特性使其对处于禁带频率范围的振动具有过滤作用,在土木工程领域可将其作为周期性隔震基础。文章提出一种基于惯性放大机制的新型周期性基础构造,并优化周期性基础的衰减域,使其对远场地震动的主要频段具有较好的衰减效果。但在衰减域外的共振峰处,周期性基础存在放大结构响应的缺陷;同时由于地震动的随机性,可能会放大结构在一些特殊地震动下的响应,因此文章将转动黏滞阻尼引入周期性基础,弥补了以上缺陷。通过频率响应分析,得到频响曲线;并进行参数分析,研究不同刚度比、质量比、偏角、阻尼比、单元个数等对周期性基础衰减域特性的影响。结果表明:此新型周期性基础能够降低原结构响应峰值的39.6%~69.2%,且对所取的44条远场地震动均有明显作用,实现了良好的衰减效果及鲁棒性。Periodic structure can be used as periodic isolation foundation in the field of civil engineering because of its unique bandgap characteristics which can filter the vibration in the bandgap frequency range.In this work,a novel periodic foundation based on inertial amplification mechanism is proposed,and the attenuation domain of the periodic foundation is optimized so that it has better attenuation effect on the main frequency range of far-field ground motions.However,at the formant outside the attenuation domain,the periodic foundation has the defect of amplifying the response.At the same time,due to the randomness of ground motions,the response of the structure under some special earthquake records may be amplified.Therefore,the rotational viscous damper is introduced into the periodic foundation in order to overcome the above defects.Based on frequency response analysis and time history analysis,the influences of different stiffness ratios,mass ratios,off-angles,damping ratios and numbers of element on the attenuation domain of the periodic foundation are studied.The results show that the novel periodic foundation achieving good attenuation and robustness can reduce the peak response of the original structure by 39.6%~69.2%,and has a significant effect on the 44 far-field ground motions taken in this study.

关 键 词：周期性基础 惯性放大机制 转动黏滞阻尼 衰减域 

分 类 号：TU476[建筑科学—结构工程]