强震作用下考虑风致疲劳的风电塔架结构破坏模式及抗震性能研究

Fatigue performance deterioration of wind turbine tower structures under long-term wind load will change its failure mode and seismic performance under strong earthquake action. Therefore, mastering its catastrophe mechanism and its seismic performance after performance deterioration is particularly important to guarantee the safe operation of wind turbine structures. Considering wind-induced fatigue performance deterioration, this research project investigates disaster mechanism and seismic performance of the wind turbine tower under the strong earthquakes. (1) Using the limited point’s responses recoded by structural health monitoring system and modal decomposition and extension technology, the whole structure strain prediction method is proposed, fatigue degradation model of wind turbine tower is established by combining with the test of standard test pieces. (2) According to the nonlinear responses of the wind turbine tower under strong earthquakes, the rules of the structural dynamic response of wind turbine tower structure under earthquake are investigated. (3) Considering the performance deterioration, the damage models and the catastrophe mechanism of wind turbine tower under the action of earthquake are discussed, and the system failure criterion and the different stage of damage boundary are ascertained. Additionally the probability seismic design and evaluation methods based on the performance of wind turbine towers are developed. The results of this research project have important guiding significance to improve our country's disaster prevention and mitigation capacity of wind turbine infrastructures.

风力发电塔架结构在长期风荷载作用下会引起疲劳性能退化，进而改变其在强震作用下的破坏模式与抗震性能。因此，掌握其在性能退化后的灾变机理及其抗震性能对保障风力发电结构的安全运营显得尤为重要。本项目在考虑风致疲劳性能退化的基础上，对风电塔架结构在强震作用下的灾变机理及抗震性能展开研究。（1）利用结构健康监测系统有限响应测点现场实测数据，借助模态分解及扩展技术，提出全结构应变预测方法，结合标准试件试验，构建风电塔架结构疲劳退化模型。（2）通过对风力发电塔架结构体系在强震作用下的非线性响应进行分析，研究强震作用下风力发电塔架结构的动力响应规律。（3）结合性能退化模型，探究风力发电塔架结构体系在强震作用下的破坏模式及灾变机理，确定结构体系失效判定准则及不同阶段的损伤破坏界限，发展基于性能的风电塔架概率抗震设计与评估方法。本项目研究成果对提高我国高烈度区风力发电基础设施的防灾减灾能力具有重要指导意义。

风力发电作为一种风能的有效利用方式得到了广泛的推广和应用。为了捕捉更多的风能，风力发电结构逐步向大型化发展，建设场地也在不断向偏远地区、高烈度地区发展，导致风电结构的破坏模式变得更为复杂。因此，研究考虑性能退化后大型风电结构强震作用下的灾变机理及其抗震性能对保障高烈度区风力发电结构的安全运营显得尤为重要。因此，本项目主要围绕考虑风致疲劳性能退化对风电塔架结构在强震作用下的灾变机理及抗震性能展开研究。通过研究主要取得以下研究成果：（1）基于 PEER 数据库选取地震动作为输入样本，分析近断层竖向加速度分量的频谱特性与典型远场地震动的区别，考虑风力发电机的低阻尼特性，建立近断层脉冲型地震动的设计速度反应谱。（2）建立考虑“叶片-机舱-塔架-基础”的风电结构精细化有限元模型，研究不同场地上的风力发电结构在近断层脉冲型地震动、近断层非脉冲地震动和远场地震动作用下风力发电结构动力响应及破坏模式，给出结构在强震作用下的破坏模式。（3）考虑地震竖向地震动分量、叶片旋转效应及土-结构相互作用，研究了其对结构影响的影响规律，并给出风-震耦合作用下的风电结构动力响应的变化规律。（4）将B-R准则及相图法引入结构动力分析，提出一种基于B-R准则及相图法的风力发电塔架结构动力屈曲分析方法，为结构设计提供依据。本项目研究成果对提高我国高烈度区风力发电基础设施的防灾减灾能力具有重要指导意义。