Maintenance of wind turbine towers is currently a manual process that requires visual inspection and bolt tightening yearly. This process is costly to energy companies and its necessity is not well-defined. In this study, two Rayleigh-based distributed fiber optic sensing technologies are evaluated and compared for their ability to monitor the dynamic structural behavior of a model wind turbine tower subject to free and forced vibration. They are further tested for their ability to detect structural phenomena associated with loose bolts and material damage within the tower. The two technologies examined are optical frequency domain reflectometry (OFDR) and phase-based optical time domain reflectometry (\(\phi\)-OTDR), which is a technology used in distributed acoustic sensing (DAS). OFDR is a tested and proven strain measurement technology commonly used for structural health monitoring but can only make strain measurements over short distances (10 s of meters). OFDR was used to validate the measurements made with \(\phi\)-OTDR which can measure over much longer distances (several kilometers). Due to its sensing distance capability, \(\phi\)-OTDR is a promising technology for monitoring many wind turbines networked together with a single fiber optic cable. This study presents a first-of-its-kind use of \(\phi\)-OTDR for structural health monitoring to demonstrate its capabilities.

风力涡轮机塔架的维护目前是手动过程，需要每年进行外观检查和螺栓紧固。该过程对能源公司而言成本高昂，其必要性还没有明确定义。在这项研究中，评估并比较了两种基于Rayleigh的分布式光纤传感技术，以监测受自由振动和强迫振动影响的模型风轮机塔架动态结构行为的能力。他们进一步测试了它们检测与螺栓松动和塔内材料损坏相关的结构现象的能力。考察的两种技术是光频域反射仪（OFDR）和基于相位的光时域反射仪（\（\ phi \）-OTDR），这是在分布式声学传感（DAS）中使用的技术。OFDR是一种经过测试和验证的应变测量技术，通常用于结构健康监测，但是只能在短距离（10 s米）内进行应变测量。OFDR用于验证使用\（\ phi \）- OTDR进行的测量，该测量可以测量更长的距离（几公里）。由于具有感应距离功能，\（\ phi \）- OTDR是一种有前途的技术，可用于监视使用单根光纤电缆联网的许多风力涡轮机。这项研究提出了\（\ phi \）- OTDR在结构健康监控中的首次使用，以证明其功能。