Behaviour of transmission line conductors under tornado wind

  • Hamada, Ahmed (Department of Civil and Environmental Engineering, Faculty of Engineering, The University of Western Ontario) ;
  • El Damatty, Ashraf A. (Department of Civil and Environmental Engineering, Faculty of Engineering, The University of Western Ontario)
  • Received : 2015.01.28
  • Accepted : 2016.02.02
  • Published : 2016.03.25


Electricity is transmitted by transmission lines from the source of production to the distribution system and then to the end users. Failure of a transmission line can lead to devastating economic losses and to negative social consequences resulting from the interruption of electricity. A comprehensive in-house numerical model that combines the data of computational fluid dynamic simulations of tornado wind fields with three dimensional nonlinear structural analysis modelling of the transmission lines (conductors and ground-wire) is used in the current study. Many codes of practice recommend neglecting the tornado forces acting on the conductors and ground-wires because of the complexity in predicting the conductors' response to such loads. As such, real transmission line systems are numerically simulated and then analyzed with and without the inclusion of the lines to assess the effect of tornado loads acting on conductors on the overall response of transmission towers. In addition, the behaviour of the conductors under the most critical tornado configuration is described. The sensitivity of the lines' behaviour to the magnitude of tornado loading, the level of initial sag, the insulator's length, and lines self-weight is investigated. Based on the current study results, a recommendation is made to consider conductors and ground-wires in the analysis and design of transmission towers under the effect of tornado wind loads.


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