The global growth in wind energy suggests that wind farms will increasingly be deployed in seismically active regions, with large arrays of similarly designed structures potentially at risk of simultaneous failure under a major earthquake. Wind turbine support towers are often constructed as thin-walled metal shell structures, well known for their imperfection sensitivity, and are susceptible to sudden buckling failure under compressive axial loading.ududThis study presents a comprehensive analysis of the seismic response of a 1.5-MW wind turbine steel support tower modelled as a near-cylindrical shell structure with realistic axisymmetric weld depression imperfections. A selection of 20 representative earthquake ground motion records, 10 ‘near-fault’ and 10 ‘far-field’, was applied and the aggregate seismic response explored using lateral drifts and total plastic energy dissipation during the earthquake as structural demand parameters.ududThe tower was found to exhibit high stiffness, although global collapse may occur soon after the elastic limit is exceeded through the development of a highly unstable plastic hinge under seismic excitations. Realistic imperfections were found to have a significant effect on the intensities of ground accelerations at which damage initiates and on the failure location, but only a small effect on the vibration properties and the response prior to damage. Including vertical accelerations similarly had a limited effect on the elastic response, but potentially shifts the location of the plastic hinge to a more slender and, therefore, weaker part of the tower. The aggregate response was found to be significantly more damaging under near-fault earthquakes with pulse-like effects and large vertical accelerations than far-field earthquakes without these aspects.
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机译：全球风能的增长表明，风电场将越来越多地部署在地震活跃的地区，大面积类似设计的结构可能会在大地震下同时发生故障。风力涡轮机支撑塔通常被构造为薄壁金属壳结构，以其不完善的灵敏度而闻名，并且在轴向压缩载荷下容易发生突然的屈曲破坏。 ud ud本研究对1.5的地震响应进行了全面分析。兆瓦级风力发电机钢支撑塔，建模为近似圆柱的外壳结构，具有逼真的轴对称焊缝凹陷缺陷。应用了20个代表性地震地震动记录的选择，分别是10个“近断层”和10个“远场”，并使用地震中的侧向漂移和总塑性能量耗散作为结构需求参数来探索总地震响应。 ud塔被发现具有很高的刚度，尽管在地震激发下，由于高度不稳定的塑料铰链的发展，在超过弹性极限之后不久，整体坍塌可能会发生。发现实际的缺陷对破坏开始的地面加速度强度和破坏位置有重大影响，而对振动特性和破坏前的响应影响很小。类似地，包括垂直加速度在内对弹性响应的影响有限，但可能会将塑料铰链的位置转移到更细长的位置，从而使塔架的较弱部分。与没有这些方面的远场地震相比，在具有脉冲效应和较大垂直加速度的近断层地震中，总响应的破坏性要大得多。
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