Ahmed Hamada

Date of Award


Degree Type


Degree Name

Master of Engineering Science


Civil and Environmental Engineering


Dr. A. A. El Damatty


The majority of transmission line failures that have occurred in the past have been attributed to High Intensity Wind (HIW) events in the form of tornadoes and downbursts. A numerical model is developed in the current study to assess the performance of transmission lines under tornado wind loads. The tornado wind field used in the study is based on a Computational Fluid Dynamics (CFD) analysis that was developed and validated in a previous study. Using field measurements, the CFD data is used to estimate the wind fields for F4 and F2 tornadoes. A three-dimensional nonlinear finite element model is developed, and includes a simulation for the towers and the lines. The wind forces associated with the tornado fields are calculated and later incorporated into the numerical model. A comparison is carried out between the forces in the members resulting from both the F4 and F2 tornado wind fields, and those obtained using conventional design wind loads. The study is further extended to represent the first

comprehensive investigation that assesses the effect of varying the relative location of the tornado to the tower on the structural performance of the transmission line system. The structural behaviour of the tower under the critical loading cases is described. The nonlinear numerical model is also modified to assess the dynamic behaviour of the transmission line system resulting from the translation motion of the tornado. Dynamic analysis is performed using two different tornado paths. The study reveals the importance of considering tornadoes when designing transmission line systems.



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