摘要
利用振动台试验研究了由砌体、混凝土加固墙板、顶部隔震钢框架组成的复杂结构的阻尼比特性.首先,建立了5层加固、加层不隔震以及加层隔震3种试验模型;然后,利用特征系统实现算法(ERA)对这3种模型的扫频数据进行模态拟合,识别试验模型在不同地震波输入量级下的结构阻尼比,并分析其随地震波输入量级的变化规律.试验结果表明,对于非隔震结构,随着地震波输入量级的增加,结构发生刚度退化,结构阻尼比增加;对于加层隔震结构,随着地震波输入量级的增加,隔震层下部的砌体结构损伤不断累积,使得上部结构与下部结构的刚度比增加,整体结构的一阶阻尼比减小,二阶阻尼比增加.试验数据分析所得的3种试验模型的阻尼比变化规律与现有理论分析结果一致.该试验结果为由不同材料组成的不同结构体系在地震作用下的阻尼比取值提供了相关依据及参考.
The damping ratio of a complex structure composed of masonry,concrete reinforced wall and isolation steel framework was studied by shaking table tests.First,three test models,five-story strengthening structure,strengthening-adding-story structure and strengthening-adding-story isolation structure,were set up.Then,the sweeping date of these three models were fitted by the eigensystem realization algorithm（ERA）.The damping ratios of these test models were identified under the different levels of the ground motions and the variation of damping ratios with the increase of the ground motions were studied.The experimental results show that,with the increase of ground motions,the stiffness of the non-isolated structure decreases while the damping ratio of the structure increases.For the mid-story isolation structure,the damage of masonry accumulates gradually with the increase of ground motions,inducing the increase of the stiffness ratio between superstructure and substructure,the decrease of the first-order damping ratio and the increase of the second-order damping ratio of the structure.The development trends of the damping ratio of these three test models are accorded with the theoretical analysis.The experimental results provide basis and reference for choosing proper damping ratios for different structure systems with different materials.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第6期1151-1156,共6页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(50908115
51178219)
江苏省普通高校研究生科研创新计划资助项目(CXLX12_0438)
关键词
加固加层隔震结构
阻尼比
振动台试验
刚度比
strengthening-adding-story isolation structures
damping ratio
shaking table test
stiffness ratio
