非线性悬吊质量摆对输电塔减振控制的研究

Aseismic control of transmission towers with nonlinear suspended mass pendulums

针对悬吊质量摆减控制研究中小摆角线性分析的局限性,提出考虑悬吊质量摆大摆角非线性特性来计算结构体系动力响应的方法,将传统分析中的悬吊质量摆的线性刚度修正为非线性。以一输电塔为例,通过线性和非线性计算结果对比可知,当摆角过大时线性计算方法不满足线性小摆角条件,而非线性计算方法则可很好模拟质量摆在大摆角下的响应。通过参数分析讨论了正弦激励周期、摆长及质量比对输电塔减震率的影响。选取三条不同场地地震记录,计算输电塔附加质量摆体系的地震响应,结果表明在不同场地条件下,输电塔均具有明显的减震效果。

Due to the limitation of linear analysis for a suspended pendulum control system with small swing angle, a method analyzing dynamic response of a structure considering nonlinear stiffness of pendulum was proposed here.Taking a 500 kV transmission tower as a numerical example and comparing the results under linear and nonlinear conditions,it was found that the swing angle of pendulum may exceed the limitation of linear assumption and the nonlinear analysis can simulate a structural dynamic system with large swing angles of pendulum perfectly.The effects of parameters of the control system including excitation periods,pendulum length and mass ratio on the seismic reduction ratio of the transmission tower were studied.Three seismic records were used to calculate the dynamic response of the transmission tower with suspended pendulums.The results showed that the mitigation effect of suspended pendulums on the structural response is very obvious under different seismic excitations.