考虑阻尼影响的新型周期性基础性能研究

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...

Research on performance of a novel periodic foundation considering damping effects

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.