Seven Years SHM of Offshore Wind Turbine Foundations: Review, Experiences and Outlook

Abstract

Wölfel Engineering is a leading expert on the design and provision of SHM systems for offshore wind turbines, as well as the assessment of their structural integrity based on the implementation of sophisticated data evaluation algorithms. This contribution aims to provide an insight into the SHM results of offshore wind turbine foundations in numerous wind farms over the last seven years, focusing on presenting an overview of the evolution of SHM concepts, monitoring goals and features monitored for structural assessment – alternatively referred to as key performance indicators (KPIs). Over the years, design approaches have become more accurate, alongside with the continuous increase of the size of the structures. Examples from offshore wind farms are used in order to show the effect of these evolutions to KPIs, such as the natural frequencies and the fatigue life consumption. The challenges met in industrial SHM applications for offshore foundations are discussed. A novel approach to SHM, the agile SHM concept, is Wölfel’s answer to the future requirements on monitoring accuracy and reliability. The proposed concept enables the efficient exchange of information between the results of the SHM system and the design process, so that the design model is at all times an accurate representation of the real structures.