输电塔线体系风致覆冰脱落动力响应的研究

建立了两塔三线模型,采用数值实验研究了输电线路的动力特性和中跨覆冰导线发生舞动时覆冰脱落、覆冰不脱落这两种工况的输电塔线系统的动力响应特性,探讨了不同风速下二者响应的差异.计算模型考虑了输电线的初始变形和初始应力.分析结果表明,塔端不平衡张力和邻跨导线横向振幅都随着风速的增加而增大,舞动导致的覆冰脱落使邻跨导线横向振动频率大幅增加,竖向回弹高度相对减小,而中跨的竖向回弹高度和横向振幅分别增加了73.9%和57.7%左右.舞动导致的覆冰脱落对线路的影响不容忽视,在实际线路的设计中应加以特别的考虑.

Research on Dynamic Response of Wind-induced Ice-shedding of Transmission Tower-line System

Wind-induced ice-shedding makes transmission-line tower system produce complex dynamic responses. This paper built a finite element model of a three-span transmission-line system. When galloping occurs in mid-span conductors, with or without ice-shedding, the dynamic responses of the transmission-line tower system were analyzed through numerical experiment, and the differences of the two load cases under different wind speeds were also studied. Besides, this paper also analyzed the dynamic characteristics of the system. In the model, the initial deformation and stress of the conductors is taken into account. The results show that the unbalanced tension of the tower head and the transverse conductor-amplitude of adjacent spans get larger with the increase of wind speed. The transverse vibration frequency of adjacent-span conductors led by ice-shedding increases dramatically, and the vertical rebound height decreases relatively. The vertical rebound height and transverse amplitude of the mid-span increase by about 73.9% and 57.7% respectively, to which special attention should be paid in the design of transmission lines.