两种离散方法对覆冰四分裂导线舞动特征的影响

Influence of two discrete methods on galloping characteristics of iced quad bundle conductor

首先基于Hamilton变分准则推导了覆冰导线三自由度耦合动力学方程组,接着采用两种离散方法离散动张力应变,一种是直接使用Galerkin法离散,另一种是先将动张力应变等效处理,然后再使用Galerkin法离散。由风洞试验测得新月形覆冰四分裂导线的气动力系数,并将各子导线的气动力系数等效,接着利用泰勒展开式拟合气动力系数,选取攻角55°进行舞动分析。基于Runge-Kutta法得到两种离散方法下的位移响应曲线,通过对比这两者位移响应曲线的差别,发现不同的离散方法对系统的相位、频率以及振幅皆有一定程度的影响。本文研究有助于理论建模的完善,并能给予实际工程一些指导。

Based on the Hamilton’s principle,the coupled three-degree-of-freedom dynamic equations for an iced conductor are derived,and then two discrete methods are used to discretize the dynamic tension.One is to use Galerkin method directly,and the other is to treat the dynamic tension equivalently among the span length,and then use Galerkin method.Based on a wind tunnel test,the aerodynamics coefficients of the iced quad conductor is obtained,and the aerodynamics of each sub-conductor is equivalent.Then,the aerodynamic coefficients are fitted by Taylor’s series,and the angle of attack which is 55° is used to analyze of galloping characteristics of the iced quad conductor.Based on Runge-Kutta method,the displacement response of the two discrete methods are obtained.By comparing the differences of the displacement responses obtained by the two discrete methods,it is found that the two discrete methods have a certain influence on the phase,frequency and amplitude of the system.The research in this paper can be helpful to the improvement of theoretical modeling and can give some guidance to practical engineering.