Dynamic Behavior Of Lattice Tower System Under Wind-rain Forces

The transmission tower-line system belongs to high-compliance structure and spans large,the dynamic response is very significant under wind, rain and cladding ice loads. At presentthe transmission tower research work is focused on the seismic wind resistance andanti-seismic, the research on wind-rain resistance and cladding ice resistance is still in theearly stages of development. Due to the complexity of the tower line system coupling, theresearch on its dynamic response under wind, rain, cladding ice loads is lack ofcomprehensive understanding. It is the most economic and effective means to research thedynamic response characteristics of the transmission tower-line coupling system throughnumerical analysis.This paper aims at discussing actual condition of tower collapsed most commonly occursin the exciting of environmental loads, such as wind-rain and ice with cover. The maincontent of this research as follow:Firstly, spectrum model based on Kaimal spectrum produce time-histories of pulsantwind speed using harmonic superposition method; Furthermore, we can identify computingmethod with respect to rain loads and the combination principle of wind-rain loads; we canalso simulate wind-rain and ice with cover of transmission towers line system at differentHeight using Chaine and Skeate S models,considering the classification of rainfall andcombining computing method of ice with cover;Secondly, we establish finite element model transmission tower and transmission wiresand conduct dynamic analysis, respectively. Then finite element analysis model onTransmission tower-line system of three towers and two spans is built on That Basis; andanalyzes its dynamic characteristics;Finally, under wind lonely and wind, rain, cladding ice combination incentive, doresearch on the dynamic characteristics of the transmission tower and transmission tower linesystem respectively. Analyzes the distribution rule in response time history of the tower topdisplacement and tower leg axial force, and the power spectrum change of the displacementand acceleration. Under different environment load combination, make research on energytransfer law between lines and tower in tower line system coupling. Do strength calculation totower legs and lines, then analyse accident causes of the pour tower;The results of the study show that, the design of the transmission tower-line structureshould consider the effect on tower line system coupling, and the dynamic response analysisresults under wind, rain, cladding ice combination incentive are increased obviously thanwind load alone.