Development of a physics-based multi-scale progressive damage model for assessing the durability of wind turbine blades

A physics-based multi-scale progressive damage model was developed for predicting the durability of wind turbine blade structures. Computational micromechanics was coupled within a continuum damage mechanics (CDM) framework, and implemented through a user-defined subroutine within commercial finite element software, for evaluating sub-critical damage evolution and stiffness degradation of the blade structure. The study is the first step in developing an accurate prediction model for composite wind turbines that accounts for the multi-scale nature of damage in rotor blades. The quasi-static and fatigue simulation results demonstrate the ability of the model to predict the evolution of damage in the critical regions of the blade structure, which is an important contribution and essential for increasing the accuracy of damage tolerance analyses and for certification of composite structures. A parametric study of blade geometric parameters also revealed a correlation with damage evolution, providing valuable insight for optimization of blade designs.