半柔性悬挂减振结构振动台试验研究

Shaking table experiment of semi-flexible suspended-floor structures

通过对设置黏滞流体阻尼器的半柔性悬挂结构进行地震模拟振动台试验,分析了主结构与悬挂楼面的质量比、连接方式、阻尼器的分布和层间斜撑对悬挂结构动力特性和响应的影响。试验结果表明:采用阻尼器连接主结构和悬挂楼面,可改变结构频率和振型阻尼比;当悬挂楼层侧向刚度较小时,结构振型表现为柔性层与悬挂楼面的耦合剪切变形;当增设斜撑后,结构第一振型为柔性层的层间变形;阻尼器连接时模型的主结构地震响应小于刚性连接的普通悬挂结构,通过增设斜撑可进一步提高减振效果;与自由悬挂结构相比,采用阻尼器连接的悬挂减振结构能够较好地抑制悬挂楼面相对于主结构的位移和悬挂楼面的层间位移;设置斜撑后,能够进一步减小悬挂楼面的层间位移,同时弱化了阻尼器不均匀对减振效果的影响。

A Shaking table experiment of a semi-flexible suspended-floor structure（SFSS） equipped with fluid viscous dampers had been conducted.The effects of link types and mass ratios between the primary structure and suspended floors,distribution patterns of dampers and diagonal braces on the dynamic characteristics and responses of suspended-floor structures were verified.Test results showed that the frequencies and mode damping ratios of the SFSS installed with dampers were adjusted and its first three modes were mainly governed by the coupling shear drift of suspended floors and the flexible layer when the shear stiffness of suspended floors was relatively small.After diagonal braces were installed,the first mode was governed by the story drift of the flexible layer.The maximum top floor displacement of the SFSS with dampers was smaller than traditional suspended-floor structure and installing diagonal braces can improve the vibration-controlling effect.Moreover,the SFSS with the dampers can effectively decrease the displacements of suspended floors relative to the primary structure and the story drifts of suspended floors in comparison with the suspended-floor structures without links.Besides,the story drifts of suspended floors and the influence of the uniform distribution of dampers on the controlling responses can be decreased when diagonal braces were installed.