被动式自适应悬吊质量摆对大跨空间结构振动控制的研究

Research on Vibration Control of Large-span Spatial Structures with a Passive Adaptive Suspended Mass Pendulum

针对悬吊质量摆在地震作用下动力响应过大而导致的大摆角频率失调问题,提出一种基于弧形支座的被动式自适应悬吊质量摆,以保证其在振动过程中周期保持恒定并应用于大跨空间结构的振动控制。首先推导出在大摆角振动中能使悬吊摆的周期保持恒定的弧形支座的数学方程,接着利用拉格朗日方程原理建立了自适应悬摆—大跨空间结构耦合体系的运动方程。针对悬吊质量摆仅能控制结构水平振动的缺点进行改进,使其可以同时控制大跨空间结构水平和竖向的动力响应。以一单层网壳结构为例,研究了其在不同的水平和竖向地震作用下的减振效果,并与传统的悬吊摆进行对比。结果表明,改进后的自适应摆对大跨结构水平和竖向地震响应的峰值和均值都有较好的减振效果,减振率最高可达65%,尤其是大摆角时减振效果明显优于传统的悬吊质量摆。

In this paper,a passive adaptive suspended pendulum(ASMP)based on curved support is proposed to reduce the seismic response of the large-span spatial structures.Firstly,the mathematical equations for the curved support are derived,which can keep the period of the suspended mass pendulum constant at a large angle of swing.Based on the principle of Lagrange equations,the motion equation of the coupling system of ASMP and long-span spatial structures is established.The shortcomings that the suspended mass pendulum can only control the horizontal vibration of the structure are overcome so that the horizontal and vertical dynamic response of the large-span space structure can be simultaneously controlled.Furthermore,to verify the vibration control effectiveness of the ASMP,a reticulated shell structure was investigated under different horizontal and vertical seismic records.The results reveal that the ASMP has a significant mitigation effect on the peak and average values of the horizontal and vertical seismic response of the structure and the vibration reduction rate can reach up to65%,which is obviously better than normal suspended mass pendulums.