Analysis On Vibration Control For Long-span Transmission Tower-line System Under Wind Load

As a kind of important life-line system, transmission tower-line system has some particular characteristics:with high-rise tower, flexibility and large-span, has intensively nonlinear; Due to the characters of the structure, the main design load is wind-load. According to the statistics, the wind-induce vibration fatigue and collapse are the most usual destruct form in the construction of transmission tower. So, the research in this aspect is of much importance.The existence of turbulent wind makes great difference how long-span transmission tower-line system behave between dead load and under dynamic excitation. The vibration of transmission conductor exerts great influence on the transmission tower, making it more complex. This paper conducts wind-vibration-control analysis on a long-span transmission tower-line system in Jinan, based on nonlinear time history analysis of SAP2000.The thesis is divided into such parts as follows:Firstly, responsed to the basic characteristics of wind and the transmission tower, the author simulated the stochastic fluctuating that can be used in the posterior analysis by the harmonic wave superimposing method.Secondly, using SAP2000, the author establishes refinement three-dimension finite element modal of transmission tower-line system. Besides, this paper conducts analysis on the dynamic characteristics of transmission tower.Thirdly, this paper discovers the operation mechanism of passive energy dissipation system including suspended mass pendulum and tuned mass damper, and successfully simulates them in the finite element soft SAP2000. Then calculates the vibration decreasing ratio of suspended mass pendulum and tuned mass damper and selects a more suitable vibration-control programme for long-span transmission tower-line system.At last, the author conducts parameter analysis on tuned mass damper. In another word, this paper discovers the variation trend of vibration decreasing ration when the mass ration, frequency ratio and damping ratio varies, which are considered to be the most important parameters of tuned mass damper. Then compares the calculation results and makes out a relatively best parameters for tuned mass damper of which a better vibration decreasing ratio can be accessed.