Reliability-Based Lifetime Fatigue Damage Assessment of Offshore Composite Wind Turbine Blades

This paper presents a method for stochastic deterioration modeling and fatigue damage assessment composite wind turbine blades operating in offshore environments. The of the is analyzed assessed based on estimates applied loads along blade span, stress analysis, crack evolution, lifetime probability failure. complex states are mainly caused by aerodynamic generated corrected element momentum theory, gravity loads, centrifugal loads. then investigated basis actual propagation process. gamma process introduced to calculate failure various critical limits, these results together with lifecycle cost analysis employed determine optimum maintenance strategy. Finally, numerical example National Renewable Energy Laboratory 5-MW adopted demonstrate applicability proposed method. show that approach can provide reliable tool estimating states, evaluating damage, analyzing probability, optimizing repair time blade.