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为解决常规的锥型风力发电塔筒在大型风电机组中的制作、加工和施工运输成本大幅上升的问题,提出了新型组合式风力发电塔架结构以及在组合式塔架连接处采用过渡段连接的改进方案。分析了组合式塔架的静力学特点和最佳过渡段设计方案,并与常规锥台型塔筒的力学性能进行了对比。结果表明,组合式塔架在额定工况和暴风工况下均满足强度和刚度要求;过渡段最佳厚度为255mm、高度为25m,改进后的塔架提高了组合式塔架的力学性能;暴风工况下,改进后的组合式塔架塔顶位移比锥台型塔筒约小17%,且总体上组合式塔架的用钢量明显小于锥台型塔筒,具有良好的经济适用性能。 相似文献
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为分析风-震共同作用下风力机塔架的动力响应,基于Wolf方法建立了土-构耦合模型,通过开源软件Fast预留数据接口开发了地震载荷模块,研究了在不同土质下塔架的振动特性和响应幅值。结果表明:地震载荷极大地加剧了塔架振动,尤其是塔架一阶固有频率和二阶固有频率的振动幅值明显增大;设防烈度为8度时,塔顶振动的主要激励为地震载荷,气动载荷对塔顶振动的影响很小,可忽略不计;由于阻尼和地震反应谱特征周期不同,在不同土质下塔架的响应幅值和振动特性差异较大;与无地震相比,在额定风况下硬黏土、岩土和软土3种不同场地土质发生地震时,塔顶侧向位移分别增大了316%、242%和265%。 相似文献
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采用FAST软件对同一风场、2 MW风电机组的纯钢塔架和钢-混凝土组合塔架进行正常运行工况和急停工况的动力响应分析。结果表明:两种工况下,纯钢塔架塔顶位移响应均大于钢混塔架;在正常运行工况下,两类塔架塔顶处加速度响应受3倍、6倍风轮转速对应的频率影响较大,且纯钢塔架受二阶振型影响明显;急停工况下,塔架振动加剧,纯钢塔架相比于钢混塔架更加敏感,两种塔架前后振动方向加速度响应主要受塔架一阶振型影响,而侧向振动方向加速度响应受塔架二阶振型影响明显。 相似文献
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以近海DTU 10 MW超大型风力机为研究对象,选用东海实测海床土壤参数构建桩周土水平抗力-桩基形变(p-y)曲线,并基于非线性弹簧单元建立纯砂土、纯黏土及多土层桩-土耦合效应模型,选取实测地震位移数据作为地震载荷,采用有限元方法对比研究了3种桩-土耦合效应下风力机动力学响应特性.结果 表明:多土层桩-土耦合效应下塔顶位移、塔顶前后位移及侧向位移峰值及其波动的剧烈程度小于纯砂土,但大于纯黏土,采用纯砂土或纯黏土构建桩-土耦合效应模型将导致预估响应结果不准确;不同桩-土耦合效应下,塔架一阶模态均被地震载荷诱发;地震作用时纯砂土桩-土耦合效应下塔架屈曲因子最小,多土层次之,纯黏土最大;塔架最大剪应力峰值位于塔架支撑结构处,地震作用时塔架下端易发生局部屈曲,结构设计时应重点关注此处. 相似文献
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风力机塔架在地震激励下的动力学响应研究对保证风力机安全运行具有重要意义。基于有限元软件ANSYS和Wolf土-构耦合理论对Vestas1.65 MW风力机建立较高精度有限元模型,对是否考虑土-结构耦合(Soil-Structure Interaction,SSI)效应两种条件下进行瞬态动力学分析。选用摩根希尔(Morgan Hill)地震运动,土体选用软土物性参数。结果表明:考虑SSI效应会降低风力机塔架自振频率,塔架在地震激励下的塔顶位移响应、塔顶加速度响应、塔架Mises等效应力响应和塔架剪应力响应频率有较明显下降,塔顶加速度峰值减小6.7%,塔基承受剪应力增加73.5 MPa,增幅98.9%。因此,研究风力机结构抗震设计应考虑SSI效应。 相似文献
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为保障极端复杂环境下风力机塔架的结构安全,以NREL 5 MW风力机为研究对象,基于开源软件FAST预留数据接口开发地震载荷计算模块,研究气动阻尼和地震对风力机结构响应的影响,并在机舱和基础平台安装调谐质量阻尼器(Tuned Mass Damper,TMD),对塔架的振动进行控制。结果表明:塔顶响应主要受地震载荷影响,气动载荷对其影响较小,且气动阻尼在一定程度上可以抑制塔架的动力响应,风-震耦合效应不可忽略;地震诱导塔架振动,安装TMD可有效减缓塔架振动和降低塔架弯矩,保证风力机的结构安全和运行稳定。TMD与结构质量比u=0.01,阻尼系数ξ=0.1时,减振控制效果最佳。 相似文献
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风力机塔架力学结构属典型的柔性细长弹性体,考虑到沿海一带棕榈树与近海风力机结构(同为细长柱体)所处环境的相似性,以传统筒型和仿生风力机塔架为研究对象,通过棕榈树样本参数拟合出树干外形函数,并考虑棕榈树内部维管束结构及其材料特性,分别建立了刚性、柔性和布置类维管束结构的仿生塔架3种塔架模型,进一步采用有限元方法对3种塔架进行静力学分析、模态分析与谐响应分析,并对比3种塔架的力学性能,分析仿生结构对塔架力学性能的影响。结果表明:风载荷作用下,原始塔架的最大应力主要集中在塔架底部,仿生塔架则集中在塔架底部以上;与柔性塔架相比,仿生塔架顶端位移增加了282.0%,而最大应力仅增加了18.0%,在满足塔架应力允许范围内,仿生塔架柔性更好;仿生塔架达到共振时塔顶位移响应幅值降低了22.2%,且共振频率点均偏大;与刚性塔架相比,柔性与仿生塔架的固有频率均较低,而仿生塔架的固有频率略高于柔性塔架。 相似文献
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以超大型DTU 10 MW单桩式近海风力机为研究对象,通过p-y曲线和非线性弹簧建立桩-土耦合模型,选取Kaimal风谱模型建立湍流风场,基于P-M谱定义不同频率波浪分布,并利用辐射/绕射理论计算波浪载荷,采用有限元方法对不同海况下单桩式风力机进行动力学响应、疲劳及屈曲分析。结果表明:不同海况波浪载荷作用下塔顶位移响应及等效应力峰值远小于风及风浪联合作用,其中风浪联合作用下风力机塔顶位移响应及等效应力略小于风载荷;波浪载荷对风载荷引起的单桩式风力机动力学响应具有一定抑制作用,此外相较于波浪载荷,风载荷为控制载荷;风载荷与风浪联合作用下风力机等效应力峰值位于塔顶与机舱连接处,波浪载荷风力机等效应力峰值位于支撑结构与桩基连接处;仅以风载荷预估风力机塔架疲劳寿命将导致预估不足;随着波浪载荷的增大,风力机失稳风险加大,波浪载荷不可忽略;不同海况下,风浪联合作用局部屈曲区域位于塔架中下端,在风力机抗风浪设计时,应重点关注此处;变桨效应可大幅降低风力机动力学响应、疲劳损伤及发生屈曲的风险。 相似文献
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In this paper, the seismic behavior of wind turbines sitting on a finite flexible soil layer is investigated in three‐dimensional space. A numerical algorithm formulated in frequency domain is proposed in order to simulate the dynamic soil–structure interaction (SSI). The wind turbine is discretized using finite element method (FEM) while, the underlying soil is represented by complex dynamic stiffness functions based on cone models. A parametric study consisting of 24 ground motions and three soil profiles is carried out, and different response quantities of the wind tower model are calculated and presented in the paper. The free‐field ground motions are estimated based on an equivalent linear approach using SHAKE2000 computer software. Transfer functions for total acceleration of the wind tower are obtained under the considered soil profiles and the modal frequencies of the coupled wind turbine–soil foundation are estimated. It is shown that the response quantities such as displacement, rotation, acceleration, base shear and moment are significantly affected by SSI, although the effect of SSI on the fundamental frequencies of the wind tower is insignificant. The moment and shear force distribution along the height of the tower is highly influenced as the soil stiffness decreases. The change in seismic demand distribution along the tower height because of SSI is not addressed by simplified design approached and should be carefully considered in seismic design of wind towers. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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为了研究复杂海洋环境下桩周冲刷对海上风力机动力响应的影响,以美国可再生能源实验室5 MW海上风力机为研究对象,建立风力机塔架-单桩-土体有限元模型,计入风浪和地震荷载对冲刷情况下的单桩式海上风力机进行动力响应研究。对比分析不同冲刷深度以及冲刷坡角对风力机系统固有频率和动力响应的影响。研究表明:当冲刷深度增加到二倍桩径时,风力机一阶固有频率降低至转子1P频率附近,容易引起共振;在风浪荷载以及风浪、地震联合荷载作用下,冲刷坡角不变,风力机最大位移与弯矩随着冲刷深度增加而增大,疏松土质条件下的增量大于紧密土;保持冲刷深度不变,冲刷坡角的变化对风力机动力响应影响较小。 相似文献
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为更精确研究桁架式大型海上风力机在地震载荷作用下的结构动力学响应,建立桩土模型,描述土体物理性质与桩-土间的相互作用,以桁架式支撑结构的美国可再生能源实验室(NREL)5 MW海上风力机为研究对象,建立有限元模型并分析在湍流风与地震联合作用下的动力学响应。结果表明:相较于湍流风,地震作用对桁架式海上风力机动力学响应的影响更加剧烈;地震导致塔顶位移显著增大;桁架结构与塔架的连接处存在Mises应力积聚,且在地震影响下其更为严重;地震对桩基的运动状态产生显著影响,位移最大值出现在桩底。 相似文献
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T. Zieger S. Nagel P. Lutzmann I. Kaufmann J. Ritter T. Ummenhofer P. Kndel P. Fischer 《风能》2020,23(4):1145-1153
This work compares continuous seismic ground motion recordings over several months on top of the foundation and in the near field of a wind turbine (WT) at Pfinztal, Germany, with numerical tower vibration simulations and simultaneous optical measurements. We are able to distinguish between the excitation of eigenfrequencies of the tower‐nacelle system and the influence of the blade rotation on seismic data by analyzing different wind and turbine conditions. We can allocate most of the major spectral peaks to either different bending modes of the tower, flapwise, and edgewise bending modes of the blades or multiples of the blade‐passing frequency after comparing seismic recordings with tower simulation models. These simulations of dynamic properties of the tower are based on linear modal analysis performed with finite beam elements. To validate our interpretations of the comparison of seismic recordings and simulations, we use optical measurements of a laser Doppler vibrometer at the tower of the turbine at a height of about 20 m. The calculated power spectrum of the tower vibrations confirms our interpretation of the seismic peaks regarding the tower bending modes. This work gives a new understanding of the source mechanisms of WT‐induced ground motions and their influence on seismic data by using an interdisciplinary approach. Thus, our results may be used for structural health purposes as well as the development of structural damping methods, which can also reduce ground motion emissions from WTs. Furthermore, it demonstrates how numerical simulations of wind turbines can be validated by using seismic recordings and laser Doppler vibrometry. 相似文献
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为探究不同海况及伺服系统下单桩式近海风力机的地震易损性,以DTU 10 MW风力机为研究对象,建立风浪相关的地震-湍流风-波浪多物理场模型,研究其在变速变桨伺服系统下的动力特性,基于增量动力分析方法评估其地震易损性。结果表明:变速变桨伺服系统可有效缓解风力机高风速下无地震作用时的塔顶振动;当风轮在大推力下,较小的波浪载荷一定程度上可降低风力机塔顶振动及塔底弯矩;随地震动强度增加,风力机各临界损伤状态失效概率逐渐增加;风力机地震易损性主要由地震动强度决定,波浪载荷与湍流风载荷对风力机地震易损性影响较小。 相似文献
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钢-混组合塔架是低风速地区风力机支撑结构的主要型式之一,连接段对结构的性能有重要影响,组合塔架结构设计直接影响风力机的安全与建设成本。为改善塔架的结构性能以及降低塔架造价,构建了以各塔段外径、壁厚、连接段厚度和混凝土段高度等关键几何尺寸为设计变量,以塔架的固有频率、应力、位移和稳定性等关键性态指标为约束条件,以塔架成本为目标函数的优化设计数学模型。利用模型对某3 MW风力机组合塔架进行优化设计。结果表明:优化方案的塔架总成本减少了15.7%,塔架的整体结构性能得到一定改善;混凝土段高度为塔架总高度的62%时总成本最低;考虑连接段厚度的优化模型能有效调整连接段的受力性能,有利于提高塔架整体优化的效果。考虑组合塔架连接段厚度的优化设计可为同类塔架的设计提供参考。 相似文献
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In this paper, the pattern of wind turbine tower collapse as a result of the coupled effects of wind and an intense, near‐field earthquake is investigated. The constitutive relation of the tower cylinder steel is simulated via a nonlinear kinematic hardening model, and the specific value of each parameter in the constitutive model is provided. A precise model of the tower structure coupled with the blade is created using a nonlinear, finite element method. This method is compared with the results from a static pushover test of a small cylindrical tower to validate the finite element modeling method in this research. Two earthquake wave sets are selected as inputs. One contains 20 near‐field velocity pulse‐like ground motion waves with various pulse periods; the other contains 20 ordinary far‐field ground motion waves. A wind turbine tower with a hub height of 60 m is selected as an example for analysis. The dynamic response of this tower as a result of the coupled effects of the two ground motion wave sets and a transient wind load is calculated using nonlinear time‐history analysis. The calculation results shows that the average horizontal displacement of the tower top as a result of the near‐field velocity pulse‐like ground motion is 33% larger than the case with far‐field ground motion. Finally, the seismic collapse vulnerability curve of this wind turbine tower is calculated. The seismic collapse capacity of the tower is evaluated, and the seismic collapse pattern of the tower is analyzed. 相似文献