Fatigue analysis of a tidal turbine blade in composite material

Abstract

The history of tidal power harnessing goes further back than most people may guess. Global warning, however, is a relatively recent issue. In order to preserve nature and respond to the rising electricity demands without resorting to fossil fuels, new enhanced technologies need to be developed. A good example of innovative technologies is tidal turbines. Following on the steps of wind turbines, most tidal turbines blades are made in composite materials. Understanding the structure’s behaviour in unsteady tidal environments is thus of utmost importance. In this context, an accurate assessment of the unsteady tidal flow needs to be conducted in order to predict the environmental loads the turbine blade will be subjected to, under different operational conditions. Furthermore, special attention needs to be paid to the fatigue behaviour of such materials. In fact, a universally approved fatigue assessment methodology for structures in composite material is yet to be conceived. Meanwhile, the ongoing research in this field is giving way to increasingly accurate methodologies for this purpose. One such methodology has seen the light of day in the composite materials section office at Bureau Veritas Marine & Offshore.