具位移放大机制的流体黏滞阻尼器性能及减震效果分析

Investigation on performance and seismic mitigation effect of fluid viscous damper with displacement amplification mechanism

为了解决结构层间位移过小对阻尼器性能发挥的影响,依据机械原理,应用齿轮机构,提出了1种新型具位移放大机制的流体黏滞阻尼器,然后根据幂律流体的本构关系,推导了阻尼器力学模型并分析了其耗能减震能力,结果表明该阻尼器耗能能力可放大λ^(1.2)~λ~2倍,其中λ为大小齿轮的直径比。最后选择一12层钢筋混凝土框架结构,分别按不安装黏滞阻尼器、安装普通黏滞阻尼器和安装位移放大2倍黏滞阻尼器3种工况进行多遇和罕遇水准下的时程分析,分析结果表明:安装黏滞阻尼器结构的层间位移角均有不同程度的减小,位移放大2倍黏滞阻尼器减震效果优于位移未放大的黏滞阻尼器,多遇地震水准下的减震效果好于罕遇地震水准下的减震效果;安装位移放大黏滞阻尼器,对顶层的加速度控制效果较其它楼层的好,对层间位移的控制效果好于对加速度的控制效果。

In order to deal with the issue that the relative small inter-story drift restrains the efficiency of dampers,a new-type fluid viscous damper with displacement amplification mechanism based on the mechanical principles and using gear device is proposed. Then,according to the constitutive relation of power-law fluid,the mechanical model of the damping force of the damper is derived and the energy-dissipation capacity is further analyzed. Analytical results show that the energy-dissipation capacity can be amplified by λ^（1. 2）~ λ~2,in which λ is the diameter ratio of large and small gears. Finally,a 12-storey reinforced concrete frame without damper,with normal viscous damper and with the new-type damper with displacement amplification ratio of 2 was analyzed under frequently-occurred and randomly-occurred earthquake level by time history analysis method,respectively. The analytical results show that the inter-story drift ratios of structures with dampers are reduced with different extent and the energy-dissipationeffect of dampers with displacement amplification mechanism is better than normal viscous damper. And the reduction effect is better under frequently-occurred level than rarely-occurred level. In addition,the control effect for acceleration at the top floor is the best among all floors and the control effect for inter-story drift ratio is better than for acceleration.