Span Transmission Tower Wind Reliability And Stability

Transmission line system is the very important lifeline engineer system.Its damage can result in power interruption and fire disaster and brings a great loss to the poverty. Long span transmission tower, as a kind of high-rise structure, is a key link in the whole system and has lots of characteristic sush as high rise, long span, slim shape and gentle weight and so on. These characteristics of structure decide the structure to be sensitive to wind loads which is the main dominant load for design.In this paper, based on the ZhouShan long span transimission system , 370m height tower and 2750m long span, the highest and with longest span system in China. Finite element method is a primary method in the analysis of nonlinear structure. A new kind of curved cable element is used to simulate the transmission lines, nonlinear beam and truss element that considers the effect of large displacement is used to stimulate the members of the transmission tower.In thisway, the accurate spatial finite element model of the system is established. Traditional AR method is used to simulate the time -history record of fluctuating wind. Through the ansys modal and stimulated fluctuating wind, the wind-induced respond has been calculated with single tower and towe-line system in the time domain. Based on the result, the dynamic reliability of the tower-line system has been calculated with first-surpass theory.The static stabilization of the tower-line system has been analysedwith the dynamic wind coefficient and shape coefficient that been obtained from wind tunnel test. Through analytical and calculate of the wind-induced response of a transmissiong line system,some conclusion such as dynamic reliability and static stabilization, which can be used for reference to practical engineering design, is drawn in this dissertation, time-domain analysis.