Capacity of transmission tower-line system subjected to concurrent wind and ice loads

An assessment of the capacity of the transmission tower-line system subjected to the wind and ice accretion load is carried out in the present study. Analyses are carried out using an implemented finite element model of the tower-line system by using the incremental dynamic analysis (IDA) and the nonlinear static pushover analysis (NSPA). The local buckling effect is considered in evaluating the capacity curve of the tower-line system subjected to the combined wind and ice loading by using multiple finite elements to model a single structural element of the tower. The results indicate that the capacity curve depends on the orientation of incoming wind. The comparison of the obtained capacity curves indicates that the capacity curve obtained from NSPA agrees well with that obtained by using IDA, especially if the wind loading acts along the transmission line. This indicates that one could advantageously use NSPA for the development of the capacity curve of the tower-line system subjected to wind and ice loading. Parametric investigation indicates that the amount of ice accretion and the solidity ratio of the tower which is affected by the accreted ice affects the calculated capacity curve. However, neglecting the weight of the ice accretion on the tower does not affect the obtained capacity significantly.