Wind Tunnel Investigations of Aeroelastic Electricity Transmission Tower under Synoptic and Typhoon Winds

Abstract

Wind tunnel tests of an aeroelastic tower model at a length scale of 1∶40 were conducted to investigate the dynamic responses of an electricity transmission tower under synoptic and typhoon winds. The aeroelastic tower model was successively subjected to boundary layer and typhoon wind forcing in a single wind tunnel. The purpose of this study is to assess differences of the dynamic structural responses under two types of wind forcing and understand the underlying mechanism of transmission tower failures due to strong typhoons. The results indicated that the acceleration responses of the aeroelastic tower model were composed of resonant and background parts, while dominated by the resonant counterpart, and the dynamic responses of the transmission tower could be increased by up to 30% in the along-wind and crosswind directions under typhoon wind forcing. The wind load factors determined from the experimental results under typhoon winds were generally larger than those obtained from Chinese codes and standards. Suggestions on the wind-resistant design of an overhead transmission tower in typhoon-prone areas were proposed. The dynamic wind loads should be substituted by the most conservative values among different Chinese standards in estimating the equivalent static wind loadings of overhead towers under typhoon wind forcing.