Structural Response Analysis of Transmission Lines Steel Towers when Subjected to Nondeterministic Wind Loadings

The lattice steel towers have been widely used as supports for power transmission lines.In the current project practise, the structure's dynamic behaviour usually is not considered.Considering that many accidents associated to this kind of structure occur even for wind velocities below that specified in project, it's possible that most of these accidents have been produced by dynamic actions.This way, this investigation proposes an analysis methodology that can accurately simulate the coupled behaviour between the transmission line cables and towers, when subjected to wind nondeterministic loadings, aiming to assess the displacements and forces in the steel towers.The investigated transmission line system, including the steel towers, conductors and shield wires, presents two spans of 450 m with a 32.86 m height main suspension tower in the centre and two towers at the ends.The conclusions pointed out to quantitative differences associated to the structural response when calculated based on a static linear analysis and compared to the results considering a geometric nonlinear and nondeterministic dynamic analysis.