A new paper titled “Structural health monitoring of offshore wind turbines using distributed acoustic sensing (DAS)” has been published in the Journal of Civil Structural Health Monitoring. The paper is authored by James T. Xu, Linqing Luo, Jaewon Saw, Chien-Chih Wang, Sumeet K. Sinha, Ryan Wolfe, Kenichi Soga, Yuxin Wu, and Matthew DeJong.
The study presents a first-of-its-kind application and validation of fiber-optic strain sensing for structural health monitoring of offshore wind turbines. A full-scale wind turbine was tested on the University of California, Berkeley’s shaking table, where researchers used two Rayleigh-based distributed fiber-optic sensing technologies: Optical Frequency-Domain Reflectometry and phase-sensitive Optical Time-Domain Reflectometry, the latter being a technology used in DAS.
The turbine tower was subjected to quasi-static bending and multi-directional dynamic shaking to simulate strain conditions relevant to offshore wind turbine environments. The study also examined different loose-bolt configurations at turbine flange connections. Results showed good agreement between the two sensing technologies and demonstrated that the fiber-optic system could capture both global tower deformation and local structural behavior. The effects of loose bolts were clearly identified in the strain response.
This work demonstrates the promise of DAS for long-distance, high-resolution structural health monitoring of offshore wind turbines and other large civil infrastructure systems. The findings also provide practical lessons on fiber-optic cable installation and data interpretation for future field deployment.