| With the development of industry, the demand of electric power is more and more. Theelectric power has been an indispensable part in our living now. As an efficient way ofdelivering electric power, transmission tower has an important function in process of electricpower transmission. Due to failure of transmission line structures the interruption of electricalservice can have devastating economical and social consequences. So it has much meaning tomake sure transmission towers working safety.Due to the tall and slender characters of tower, the main design load is wind. At the sametime, the tower often vibrates severely subject to rain-wind induce to be destroyed. So therain-wind induced effect of tower can't be neglected. There are some problems in the criteriondesign of tower, for example, the effect of lines is not considered in dynamic analysis, thewind toad is simplified to equivalent mean wind load and the effect of rain is not consideredin wind resistance design. Because the rain-wind induced vibration of transmission towerrefers the couple of gas (wind), liquid (rain) and solid (steel tower), it is complex, so there isnot definite understanding of mechanism, and the theory research is minute quantity. Foraccurate grasping the dynamic characters and the rain-wind induced response of structure, thethree towers and two lines structure model is build for dynamic analysis.Firstly, the basic characteristics of wind are investigated. The kaimal spectrum is chosenas target spectrum. Then the stochastic fluctuating wind is simulated by harmonic wavesuperimposing method.Secondly, the class, intensity and characteristic of rain are investigated. By the M-P rainspectrum, the simulation method of rain is presented. Based on the simulated wind timemarching, the rain load time marching is simulated.Thirdly, in the paper the exact finite model of transmission tower-line system isestablished. The transmission tower member is simulated by BEAM24 element. The lines,which were determined by the theory of curve line element, are simulated by LINK10 element.The insulator is simulated by MPC184 element. The frequency and mode shape of thetransmission tower, line, and transmission tower line system are developed by modal analysis.The end, the dynamic analysis of the transmission tower line system is calculated subjectto wind load and rain-wind load. The results demonstrate that the rain load has effect to thedisplacement and stress of the transmission tower-line system. At the same time the effect is more when the rain is bigger. So the effect of rain shouldn't be neglected in design of thetransmission tower-line system.
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