| With the rapid development of China’s economy in recent years, the demand for electricity energy continues to increase, UHV transmission lines are gradually being widely used. In UHV transmission lines, the quality and pre-tension of the transmission lines are very large, strong wind, lightning and other reasons leading to the rupture of the(ground) wire has great influence on the transmission tower’s dynamic effect. Used the finite element method to simulate the dynamic effect of rupture line of straight-line tower in transmission tower-line system, and analyze the failure paths of the main members during the straight-line tower collapsed.First of all, the current situation of research on line breaking and dynamic of transmission tower-line system of domestic and exotic, the definition, cause and design method of progressive collapse, the theoretical knowledge of numerical simulation were introduced. Based on the practical project of UHV transmission tower-line system, the key problems to be solved in the process of finite element modeling and dynamic analysis were discussed, the dynamic characteristic of tower and tower-line system were analyzed, and the accuracy of tower-line system under dead load was verified.Secondly, finite element models of tower-line system with different numbers of straight-line towers were built, dynamic effect of the transmission tower next to the rupture lines when ruptured different numbers of wires were analysed, the number of the rupture wires when dynamic effect of rupture line was most obvious, the wire which affected dynamic effect of rupture line most, and the minimum number of transmission towers in the tower-line system when the change of dynamic effect of rupture line was not obvious with the increased of the tower’s number were identified. In addition, introduced the impact coefficient formula based on axial force, studied the impact on main members of the transmission tower next to the rupture wires when breaking four wires, and identified the members which were attacked by rupture wires most heavily.Thirdly, changed parameters such as the lateral stiffness of transmission tower next to the non-ruptured wires, the spans, the line angles, and the height differences of suspension points to anlyse the parameters influenced the dynamic effect of rupture line of the transmission tower next to the rupture wires when four wires were ruptured in a strain section, and gived the maximum values of these parameters when designed straight-line tower.Lastly, built a transmission tower-line system model with seven towers, studied the whole collapsed process of the transmission tower next to the rupture wires when a wire ruptured, and other(ground) wires ruptured, analyzed the attenuation law of the tensions in the transmission lines next to the rupture lines, identified the the failure paths of the main members during the transmission tower collapsed, suggested improving the design requirements of the invalid main materails. |
