戴靠山, 胡皓, 梅竹, 刘洋. 长周期地震下风力发电塔架结构地震反应分析[J]. 工程力学, 2021, 38(8): 213-221. DOI: 10.6052/j.issn.1000-4750.2021.02.0121
引用本文: 戴靠山, 胡皓, 梅竹, 刘洋. 长周期地震下风力发电塔架结构地震反应分析[J]. 工程力学, 2021, 38(8): 213-221. DOI: 10.6052/j.issn.1000-4750.2021.02.0121
DAI Kao-shan, HU Hao, MEI Zhu, LIU Yang. SEISMIC RESPONSE ANALYSIS OF WIND POWER TOWER UNDER LONG PERIOD GROUND MOTIONS[J]. Engineering Mechanics, 2021, 38(8): 213-221. DOI: 10.6052/j.issn.1000-4750.2021.02.0121
Citation: DAI Kao-shan, HU Hao, MEI Zhu, LIU Yang. SEISMIC RESPONSE ANALYSIS OF WIND POWER TOWER UNDER LONG PERIOD GROUND MOTIONS[J]. Engineering Mechanics, 2021, 38(8): 213-221. DOI: 10.6052/j.issn.1000-4750.2021.02.0121

长周期地震下风力发电塔架结构地震反应分析

SEISMIC RESPONSE ANALYSIS OF WIND POWER TOWER UNDER LONG PERIOD GROUND MOTIONS

  • 摘要: 风力发电在全球范围内得到大规模应用,地震活跃地区已建成和在建风电场数量逐渐增多,地震荷载成为风力发电塔设计中的重要因素。该文针对风力发电塔结构周期较长、对富含低频成分的长周期地震动较为敏感的特性,选择远场长周期地震动与近场脉冲型长周期地震动各20条,并选择20条非长周期地震动作为参照。以一座1.5 MW在役风力发电塔为例,建立其OpenSees的纤维截面梁柱单元模型,并通过现场实测数据对该模型进行了验证。在此基础上,分析了塔架结构在长周期地震下的地震响应,并讨论了近断层脉冲地震动的水平速度脉冲和竖向地震作用对塔架结构地震响应的影响。结果表明:相同峰值加速度条件下,远场长周期地震动更不利,塔顶水平位移和塔底内力均最大,峰值加速度0.15 g远场长周期地震作用与峰值加速度0.45 g非长周期地震作用相当。相对于远场长周期地震动,未发现近场长周期的水平速度脉冲对结构响应产生不利影响;其竖向地震荷载带来的竖向惯性力和P-Δ效应在一定程度上增大了塔架结构的轴力和塔底弯矩,但影响并不明显。近场脉冲型长周期地震动不利的主要因素仍然是其较大的峰值加速度。选择两条主频与塔架基频最接近的长周期地震动并调幅,进行风电塔截面塑性分析。结果表明:距塔底约12 m的截面最先发生屈服。当地震动峰值加速度达到0.5 g时,该截面进入塑性;0.6 g时,达到屈服。

     

    Abstract: The wind power generation has been widely used in the world. The number of wind farms built and under construction in seismically active areas is gradually increasing. Seismic loading has become an important factor in the design of wind turbines. In view of the dynamic characteristics of wind turbines, 20 far- and 20 near-field long period ground motions with rich of low frequency components were selected and seismic analyses of a typical wind turbine tower were performed with another 20 non-long-period ground motions as a reference. An OpenSees model was established for this 1.5 MW wind turbine using beam-column elements with fiber-sections and verified by the field measured data. On this basis, the seismic responses of the tower under long period earthquake were investigated, and the influences of the horizontal velocity pulse and the vertical seismic excitation of near-fault pulsed ground motions on the tower responses were discussed. Analysis results shown that the far-field ground motions induce more negative effects in the aspect of structural seismic responses. Under the same peak ground acceleration (PGA), the horizontal displacements at tower top and internal forces at the bottom of the tower due to ground excitation containing long period components are larger. The seismic responses of the tower under far-field ground motions with the PGA of 0.15 g were closed to that under the non-long-period ground motions with the PGA of 0.45 g. The vertical inertia force and P-Δ effects brought by the vertical seismic load increase the axial force and bending moment of the tower structure to a certain extent, but not obvious. The large PGA level is the main factor making the near-field pulsed ground motions more dangerous. Based on the fundamental frequency of the tower, two long-period ground motions were selected and scaled in order to analyze the plasticity of the cross-section. It is indicated that the cross-section at the height of 12 m yields firstly. When the peak ground acceleration reaches 0.5 g, the cross section enters of the tower plasticity, and when 0.6 g,it reaches yield.

     

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