自立式薄壁钢管结构耦合风致疲劳损伤评估与TMD控制

Self-supporting slender steel structures have been extensively applied in high-rise infrastructures for their advantages of lightweight, high-strength and high-efficiency. However, for the lack of reasonable assessment methodologies and effective control technologies, the collapses of these structures caused by the fatigue damage of the flange connections of pole to end-plate have been reported throughout the world. So as to solve this problem, this project launches the research contents as follows: (1) The alongwind-crosswind coupled wind induced vibration model of self-supporting slender steel structures will be proposed, then the wind induced vibration mechanisms of the structures under both normal wind and hurricane will be revealed. (2) The equivalent structural S-N curves will be developed by adopting conventional fatigue testing data and stress conversion factors. Then the multi-scale analysis model for wind induced stress calculation will be established. After that, a multi-scale fatigue assessment methodology using equivalent structural stress will be presented. (3) A mass-embedded integration Tuned Mass Damper (TMD) will be proposed, which is more effective for vibration control of the self-supporting slender steel structures. Then the analysis method for wind-induced vibration control using this TMD will be developed. Finally, the fatigue-based integral design theory and procedure of TMD control will be constructed. The results of this project will provide theoretical basements for the fatigue assessment and vibration control design of self-supporting slender steel structures.

自立式薄壁钢管结构由于其轻质、高强、高效等优点而广泛应用于高耸基础设施。由于对其风致疲劳损伤缺乏准确的评估方法和有效的控制手段，使得该类结构由于端板法兰连接节点疲劳损伤而引发的倒塌事故时有发生。基于此，本项目的研究内容主要包括：（1）建立自立式薄壁钢管结构顺-横风向耦合振动模型，揭示良态风和飓风环境下结构风振响应机理；（2）借助常规疲劳试验数据和应力转换系数，构建等效结构应力S-N曲线，建立自立式薄壁钢管结构风致应力分析的多尺度有限元模型，进而形成基于等效结构应力的多尺度疲劳评估方法；（3）提出适用于自立式薄壁钢管结构的质量内置一体式调谐质量阻尼器（TMD），进而建立相应的风振控制分析理论，最终形成基于疲劳性能的TMD控制一体化设计理论与方法。研究结果可为该类结构的疲劳评估和减振设计提供理论参考。

超高、大长细比的自立式薄壁钢管结构往往具有结构柔、质量轻、阻尼小等特点，对风荷载极其敏感，由风荷载导致的损伤乃至倒塌的屡见不鲜，因此本报告围绕此类结构的风灾评估方法与减振控制技术展开研究。首先，发展了用于自立式薄壁钢管结构风荷载模拟的改进谐波叠加法，开展了自立式薄壁钢管结构顺、横风向的风振响应分析；以此为基础，结合横风振动分析的升力振子法，构建了结构顺-横风向耦合风振动力学模型。随后，建立了风力发电机塔架多尺度有限元模型，基于等效结构应力法和热点应力法，结合Miner线性损伤累积准则，考虑风速、风向分布，开展了风力发电塔架节点焊接细节处的应力分布与疲劳寿命评估。提出了一体式孔隙耗能环形调谐质量阻尼器、环形TLD/TLCD和环形曲率相关形状记忆合金阻尼减振装置等减振器，并建立了其力学模型。最后，建立了结构减振体系动力方程，开展了自立式薄壁钢管结构TMD、TLD和TLCD减振试验，以此为基础构建了自立式薄壁钢管结构统一设计方法和多目标优化设计方法。研究结果表明，与实测数据和试验结果的对比表明，本项目所建立的风振响应及减振控制分析方法和分析程序具有一定的精度，能够用于自立式薄壁钢管结构的风灾评估与减振设计；试验模型的阻尼比为0.0134，安装TMD后结构等效阻尼比可达0.034，安装TLD后结构等效阻尼比超过0.040，而安装TLCD时结构等效阻尼比的均值仅为0.0267，安装减振器后结构风振响应能够有效衰减。