Abstract
This deliverable presents an optimal inspection planning framework for offshore wind turbine foundations developed within the WILLOW project. The framework combines structural health monitoring (SHM), remaining useful life (RUL) prognosis, maintenance decision policies, and operational scheduling to support cost-effective asset management throughout the wind farm lifetime.
The framework accounts for key offshore O&M challenges, including weather-dependent accessibility, vessel and personnel constraints, and uncertainty in RUL predictions. A fleet leader monitoring concept is introduced, where a subset of turbines is equipped with high-fidelity monitoring systems to improve farm-wide condition assessment through spatial extrapolation.
The framework consists of four interconnected modules: a degradation module for RUL prediction, a policy module for maintenance decision-making, an optimisation module for scheduling inspections and maintenance activities, and a Monte Carlo simulation module for scenario analysis and quantifying the value of monitoring information.
A case study demonstrates how monitoring information can reduce uncertainty and inspection-related O&M costs, while also highlighting the trade-off between SHM investment costs and operational savings for the case of corrosion. The framework provides a practical basis for evaluating monitoring strategies and supporting data-driven decision-making for offshore wind farm maintenance planning.