On the size and shape optimization of transmission line towers considering bolt slippage
Souza, RR1; Miguel, LFF1; Kaminski, J2; Rafael Holdorf Lopez1; Andre Jacomel Torii3
1 Federal University of Santa Catarina; 2 Federal University of Santa Maria; 3 Federal University of Paraíba
doi:10.20906/CPS/CILAMCE2017-0465
Resumo
The current practice for structural design of transmission towers, adopts in general, linear-elastic models (or geometrical non-linear) and 3D truss or space frame elements. However, it is recognized by engineers that some non-linear effects may appear, mostly related to the actual behavior of the connections, more specifically, the bolt slippage effect. Since the significance of such effect increases with the structural stiffness, it is possible to avoid the demand for a more complex structural analysis, by prioritizing flexible designs. Notwithstanding, it is unclear if a more complex (and costly) analysis of a stiffer structure, can lead to a better design, in comparison to a simpler analysis of a more flexible structure. In order to address this question, this paper presents a comparison between the optimization of two structures on CIGRE (2009). Where, Structure 1 is the more flexible, and have small differences from Structure 2. Although slightly, these differences increase the stiffness and consequently the bolt slippage effect. The results indicated that the consideration of the bolt slippage allows the algorithm to reach a competitive optimum design, and in some cases, eve better ones, in comparison to the structures where these effects are not significant.
Palavras-chave: Transmission tower structure; Bolt slippage effect; Size and shape optimization; Heuristic algorithm