Effect of modelling complexities on extreme wind hazard performance of steel lattice transmission towers
Effect of modelling complexities on extreme wind hazard performance of steel lattice transmission towers
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DOI：
10.1080/15732479.2019.1673783
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发表时间：
2020-06
影响因子：
3.7
通讯作者：
Yousef Mohammadi Darestani;A. Shafieezadeh;Kyunghwa Cha
中科院分区：
文献类型：
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作者：
Yousef Mohammadi Darestani;A. Shafieezadeh;Kyunghwa Cha
可靠的输电塔计算模型是提高输电系统飓风风险管理水平的关键。然而，对所涉及的复杂性及其对塔的极端风性能的影响的全面理解是不可用的。特别是，屈曲效应没有被适当地捕获，节点的破坏和塔的后屈曲行为没有被研究。此外，在存在不确定性的情况下，这些和其他复杂性对关键塔响应的贡献是未知的。本文提出了一种模拟晶格塔的方法，该方法可以捕获屈曲和后屈曲，以及接缝滑移和破坏，并分析它们的影响，同时考虑不确定性，通过OpenSEES中的一组概率非线性推覆分析。对双回路垂直格塔的计算结果表明，屈曲可使塔的承载能力降低30%。节点滑移使塔的承载能力降低6%。它也大大增加了塔的位移。在极少数情况下也会发生连接故障，从而改变了塔的故障模式。所提出的建模方法可用于输电系统的风险分析，以研究各种性能水平和改进塔的设计。
Abstract Reliable computational models of transmission towers are key to improved hurricane risk management of transmission systems. However, a comprehensive understanding of involved complexities and their effects on the extreme wind performance of towers is not available. Particularly, buckling effects have not been captured properly and the failure of joints and the post-buckling behaviour of towers have not been investigated. Moreover, contributions of these and other complexities to key tower responses in the presence of uncertainties are not known. This paper presents an approach to modelling lattice towers that captures buckling and post-buckling, and joint slippage and failure and analyses their effects, while considering uncertainties, through a set of probabilistic, nonlinear pushover analyses in OpenSEES. Results for a double circuit vertical lattice tower indicate that buckling can lead to 30% reduction in the load-bearing capacity of towers. Joint slippage reduces the load-bearing capacity of the tower by 6%. It also considerably increases tower displacement. Connection failure can also occur in rare cases and it subsequently, changes tower’s failure mode. The proposed modelling approach can be used in risk analysis of transmission systems to investigate various performance levels and improve the design of towers.