Approach to develop vulnerability curves for tidal turbine blades

The lifespan of tidal turbine blades is influenced by design quality, loading conditions, fatigue, water absorption, and unforeseen operational events. While structural testing under idealised conditions helps validate new designs, it often overlooks marine-specific effects such as water diffusion, erosion, and corrosion. This study introduces two novel approaches for generating vulnerability curves to predict blade lifespan, integrating material testing, literature data, and finite element (FE) modelling through a three-phase methodology. One approach
uses accelerated aged fatigue data at coupon scale, and the other uses water diffusivity parameters, with both relying on FE modelling. The aged fatigue data-based method, which showed fewer limitations, was selected for a case study involving a 4 m glass fibre powder epoxy composite horizontal axis tidal turbine blade. The resulting vulnerability curve demonstrates potential to improve durability predictions, reduce testing costs, and support sustainable development in tidal energy.