Wind Induced Vibration Control For Transmission Towers

Power Transmission Tower is a high-rising building popular used as the support of electric line. To be a very important lifeline engineering system, the damage of power transmission system can result in power interruption and fire disaster, which not only impact the usual construction and life, but also bring in a lot of fire disaster and a great loss to the poverty.The Jingdongnan-Nanyang-Jingmen 1000kV transmission line system's most normally straight towers'recognized height is 56 meters, the able to bear towers'recognized height is 35 meters. The form of crossing over is Able to bear --Straight --Straight --Able to bear, it is 500-520 (main span) to cross over the distance- 500. The structure of the system is super flexible and wind-sensitive structure, which determine that the analysis of wind-resistant capacity is indispensable. In this paper, based on this project, the dynamic characteristics and wind-induced responses of transmission line system under stochastic wind load are discussed, and some worthy conclusion is achieved for practical wind resistance design. The research is focused mainly on the following aspects:1. The finite element models of the electrical transmission single tower and tower-line system is established by using general finite element analysis (FEA) software ANSYS. The coupling among Tower-line-insulator is considered in calculating for a better accordance between the whole model and actual conditions. And initial on the non-linear analyzes result under gravity and initial internal force of transmission line, mode analyze is carried on whole system. The frequencies and modal shape of single tower and tower-line coupling system is achieved, the accurate formulas of T1 for single tower and tower line coupling system is formulated.2. Through the comparison between various damping devices, the lead viscoelastic damper with double layers glue elastic material and lead inside is used to control the wind performance. The lead viscoelastic damper paralleled to the connect is installed at the tower pole on angle steel avoiding weaken tower pole, and its structure is designed preliminarily in detail. According to the specific project, lay lead viscoelastic damper is laid out in seven schemes on single tower and tower-line coupling system.3. The program to simulate the wind velocity is debugged, which model the fluctuating wind velocity in this project. By using time history analytical method, the wind-induced response of single tower and tower-line coupling system is calculated with seven schemes of damping layout, and the vibrating controller impaction in time history is accomplished. The result shows that, the efficiency of the controlling system is perfect, and provides a theory principle for the experiment and the erecting in the future.