Fatigue Life of Megawatt-Scale Composite Wind Turbine Blades with Shallow-Angled Laminates

The fatigue life of megawatt-scale composite wind turbine blades implemented with shallow-angled laminates is investigated. Full dynamic simulations of a 5-MW 3-bladed horizontal-axis wind turbine were carried out to estimate the incident fatigue loads. The fatigue stress histories experienced by lay up materials were then computed using a finite-element model of the composite blade developed to ply-level details. Thereafter, the fatigue life of blade was estimated considering the 100% availability of the turbine for the site-specific annual wind distribution related to the wind turbine class IB. It is demonstrated that the application of shallow-angled laminates leads to a more durable design.