半主动电流控制阻尼器的调谐减振性能研究

随着建筑高度不断增加，低频振动严重影响其安全运行。被动式阻尼器仅在调谐点处具有良好的减振效果，存在减振带宽较窄的问题，磁性液体为解决这个问题提供了新的途径。以磁性液体为工作液体，提出一种半主动调谐式电流控制阻尼器。首先，建立了阻尼器固有频率的理论模型，表明通过调节电流可改变固有频率。其次，搭建测试平台，进行了不同激励下阻尼器的调谐减振能力测试。结果表明半主动电流控制阻尼器的减振率为22%左右，调谐液体滚球阻尼器的减振率仅为12.3%左右，且调谐液体滚球阻尼器与主结构的频率比>1.11时，减振率将低于10%,半主动电流控制阻尼器则具有良好的鲁棒性，可以有效降低位移响应，弥补了被动式阻尼器减振带宽较窄的不足。

Tuned damping performance of semi-active current controlled damper

Low frequency vibrations threaten the safe operation of high-rising structures as their height rise. Passive dampers only havegood damping effect at the tuning point and have a narrow damping bandwidth. Magnetic fluid provides a new solution to this problem. Inthis article, a semi-active tuned current controlled damper is proposed by using magnetic fluid as the working fluid. First, the theoreticalbasis for the inherent frequency is established. The theory shows that the current can change the inherent frequency. Secondly, thedamper test system is established to evaluate the tuned damping capability under different excitation. Results show that the damping rateof the semi-active current controlled damper is about 22% , and the damping rate of the tuned liquid rolling ball damper is only about12. 3% . The damping rate will be less than 10% when the frequency ratio between the tuned liquid rolling ball damper and the controlledstructure is greater than 1. 11. The semi-active current controlled damper has good robustness, which can effectively reduce thedisplacement response of the structure and make up for the shortage of the traditional passive dampers with narrow damping bandwidth.