Numerical analysis of the dynamic effects of wine-cup shape power transmission tower-line system under ice-shedding

This study aims at the dynamic response analysis and collapse simulation of wine-cup shape power transmission tower-line system under ice-shedding. A finite element model for wine-cup shape power transmission tower-line system is developed. The modeling techniques are discussed in detail. The static response under ice-accretion and dynamic response under ice-shedding of the system are both analyzed. A progressive collapse analysis of the tower-line system is also conducted. The numerical results show that the ice accretion on power transmission line mainly affects the cross arm of the tower, rather than the power transmission lines or the tower body. Middle shedding and uniform shedding are the most detrimental ice-shedding modes while end shedding has little influence on a single line. For tower-line system, asymmetric ice-shedding and the ice-shedding on two lines at the same span have more influence on the system than the ice-shedding on one line at a single span and at two continuous spans. The comparison between the numerical results and calculated results shows that the dynamic response of the power transmission line would be intensified under the influence of the tower and multi-span ice-shedding. The calculated results by using the proposed simplified formula considering the dynamic effect of tower-line system show good agreement with the simulation results. The middle V-part is the most crucial part in the standard wine-cup shape power transmission tower. This study suggests that special attention should be paid on the structural members connecting the middle V-part and other parts of the tower, whose fracture would easily trigger the collapse of the whole tower.