500 kV输电线路塔线体系舞动响应分析

通过建立连续5档塔线体系有限元模型，采用气动分析法得到了不同阻尼比下的导线张力、不平衡张力和导线舞动轨迹，分析了舞动荷载作用下杆塔动力响应。按照铁塔阻尼计算得到的舞动响应高于导线阻尼计算值。考虑塔线耦合效应后，导线舞动幅值增大，导线张力和不平衡张力减小。导线垂向运动由2个主频的多阶混合振动变为单个主频的一阶振动。当采用铁塔阻尼进行分析时，耐张塔不平衡张力超过断线张力设计值，铁塔横担下截面斜材最大应力超过设计应力，会导致横担被破坏。

Analysis on the Dynamic Responses of Tower-line System of 500 kV Transmission Line with Galloping Conductors

In this paper, a FEA model of continuous five-span tower-line system is established firstly. With different damping coefficients, the aerodynamic analysis method is applied to obtain several parameters of conductors, including conductor tensions, unbalanced tensions and galloping traces. The dynamic responses of the towers under galloping load are then analyzed. It shows that the dynamic responses calculated with the tower damping coefficient are higher than that with the conductor damping coefficient. With consideration of the tower-line coupling effect, the galloping amplitudes increase, and the conductor tensions as well as the unbalanced tensions decrease. The vertical motion of the galloping conductor changes from multi-order vibration of two-principal frequency to the first order vibration with one principal frequency. When analyzed with the tower coefficient, the unbalanced tension exceeds the designed broken tension and the stress of the diagonal member at the bottom plane of the cross arm is higher than the designed stress, which shows that the cross arm will be collapsed.