A Method of Estimating Wind Turbine Blade Fatigue Life and Damage using Continuum Damage Mechanics

In this article, an energy-based model for predicting fatigue life and evaluation of progressive damage in a full composite wind turbine blade is proposed. Itis based on the assumption that the damage growth rate in a composite material depends on the maximum value of elastic strain energy per cycle. Design, finite element modeling, and dynamic analysis of the blade have been performed using ANSYS software. The first five natural frequencies and mode shapes of the blade were calculated and dangerous nodes in the critical location were determined using the modal and harmonic analysis techniques. Obtaining critical stresses from ANSYS analysis, fatigue life of the blade at the first natural resonance frequency was estimated by the model. Results showed that the calculated life of the analyzed blade could meet the design requirement.