弹簧摆的内共振原理及其对输电塔的减震作用

Seismic vibration control of transmission tower with a spring pendulum

输电塔是重要的生命线工程,其在地震灾害下的正常运行对于经济安全和社会稳定具有重大意义。针对输电塔结构,提出利用弹簧摆的内共振特性实现非线性能量阱以减小地震响应。其基本原理是将原悬挂质量摆的的摆线改为弹簧,通过设计弹簧刚度使弹簧摆的振动和摆动模态相耦合,进而提高吸振能力。基于拉格朗日方程推导了弹簧摆的运动方程,验证了引发内共振的条件。以某输电塔为工程背景,输入多条实际地震动验证弹簧摆的控制效果。对比传统悬挂质量摆发现,弹簧摆吸振能力更强,减震效果更佳。通过改变地震输入幅值,讨论了地震强度对减震效果的影响。

Lattice transmission towers are vital components of transmission line systems,it is of great significance that it operates normally under earthquakes. A nonlinear energy sink（ NES） based on the internal resonance feature of the spring pendulum to reduce the seismic response of the transmission tower is proposed. The kinetic expression of the spring pendulum system is obtained through Lagrangian equation. The condition of the internal resonance is verified to be. A multi-mass model of a certain engineering is established to numerically verify the effectiveness of the spring pendulum. Compared with the traditional suspended mass pendulum,the spring pendulum absorbs more energy and reduces the oscillation more effectively. The intensity of the seismic record is also varied to investigate its influence on the vibration reduction ratio.