基于强几何非线性因素的覆冰导线舞动问题研究

分析了覆冰导线前三阶模态中在不同水平张力下各非线性刚度项系数与线性刚度项系数的比，通过讨论水平张力，线性恢复力、非线性恢复力与振动幅值之间的关系，确定了影响覆冰导线系统几何非线性强弱的主要因素。在此基础上，应用待定固有频率法计算了系统的稳态幅值和振动频率。数值模拟表明：各模态幅值均随风速增大而增大，且当受到强几何非线性因素的影响时，各阶模态的振动频率将远离初始频率，此时传统规范形理论的分析结果难以满足模型分析的精度要求，而本文研究结果则可以对模型的振动特性有比较准确地把握。

A study on galloping of iced conductor based on geometric strong nonlinear factors

The ratio of every coefficient of nonlinear stiffness terms to coefficient of linear stiffness term at different horizontal tension is analysed，which in the first three vibration mode．Through discussion relationship between amplitude of vibration and horizontal tension，linear restoring force as well as nonlinear restoring force，the main factors that influence strong or weak geometric nonlinearity of icing conductor system were determined．On the basis，the steady state amplitudes and vibration frequency of system were calculated with undetermined natural frequency method，numerical results show the amplitudes of vibration increase with wind velocity increase in each vibration mode，and frequency of each order vibration mode would deviate from original fundamental frequency while system was subjected effect of geometric strong nonlinearity．The analysis results of conventional normal form was difficult to meet accuracy requirements of model analysis，and the analysis results in this paper could relatively accurately grasp vibration characteristics of model．