This paper presents a framework for fatigue monitoring on linear components of a structure subjected to unknown loads using a limited number of output-only vibration measurements. It exploits virtual sensing techniques to estimate the dynamical responses, including virtual multiaxial strain/stress time histories. It applies joint input–state estimation algorithms to predict the dynamical response of the structural components. The resulting virtual multiaxial stress histories are used to compute the fatigue load cycles and corresponding fatigue damage. The proposed streamline approach allows the use of different available methodologies for virtual sensing and multiaxial fatigue analysis. A numerical validation example is provided using the tower of a reference wind turbine model subject to realistic wind loads. The proposed procedure can be adopted over a monitoring period to produce a global fatigue damage accumulation map from limited vibration data. It thus provides realistic fatigue damage accumulation information for a component based on the actual operational conditions of a structure.

中文翻译：

---

使用虚拟传感进行多轴疲劳监测的简化方法

本文提出了一个框架，用于使用有限数量的仅输出振动测量对承受未知载荷的结构的线性部件进行疲劳监测。它利用虚拟传感技术来估计动态响应，包括虚拟多轴应变/应力时间历程。它应用联合输入-状态估计算法来预测结构部件的动态响应。由此产生的虚拟多轴应力历史用于计算疲劳载荷循环和相应的疲劳损伤。提议的流线型方法允许使用不同的可用方法进行虚拟传感和多轴疲劳分析。使用受实际风载荷影响的参考风力涡轮机模型的塔架提供了一个数值验证示例。建议的程序可以在监测期间采用，以根据有限的振动数据生成全局疲劳损伤累积图。因此，它根据结构的实际操作条件为部件提供真实的疲劳损伤累积信息。