基于非线性能量阱的悬吊摆对输电塔-振动控制的研究

针对输电塔结构在地震作用下动力响应过大的问题,提出一种基于非线性能量阱的悬吊摆以降低输电塔的动力响应。首先利用拉格朗日方程推导了这种悬吊摆的运动方程,再以一单自由度结构为例,建立了摆式非线性能量阱—结构的动力方程,计算了摆式非线性能量阱在正弦激励下的减振效果,并对正弦激励周期、悬吊摆周期、立方刚度、质量比等参数对减振效果的影响进行了分析。最后选取一柔性输电塔为例,研究了不同地震作用下摆式非线性能量阱的减振效果,并与传统的悬吊质量摆和线性弹簧摆进行对比。结果表明,在地震作用下,摆式非线性能量阱对输电塔动力响应的峰值和均值都有较好的减振效果。

Vibration Control of Transmission Towers with a Suspended Pendulum based on Nonlinear Energy Sink

In this paper, a suspended pendulum based on nonlinear energy sink (NES) is proposed to reduce the seismic response of the transmission tower. The kinetic equations of the suspended pendulum based on nonlinear energy sink are established. Then taking a single-degree-of-freedom structure as a numerical example, the kinetic equations are obtained to compute the vibration suppression effect of the pendulum-type NES under the sine excitation and a parameter study is performed considering the influencing parameters of the control system, including the excitation periods, pendulum period, cubic stiffness and mass ratio on the maximum displacement of the structure. Furthermore, the vibration control effectiveness of a pendulum-type NES is validated through analyzing a transmission tower under four types of seismic records. The results reveal that the pendulum-type NES has a clear mitigation effect on the peak and average seismic response of the tower.