Research on Fatigue Damage Behavior of Main Beam Sub-Structure of Composite Wind Turbine Blade.

Given the difficulty in accurately evaluating the fatigue performance of large composite wind turbine blades (referred to as blades), this paper takes the main beam structure of the blade with a rectangular cross-section as the simulation object and establishes a composite laminate rectangular beam structure that simultaneously includes the flange, web, and adhesive layer, referred to as the blade main beam sub-structure specimen, through the definition of blade sub-structures. This paper examines the progressive damage evolution law of the composite laminate rectangular beam utilizing an improved 3D Hashin failure criterion, cohesive zone model, B-K failure criterion, and computer simulation technology. Under static loading, the layup angle of the anti-shear web has a close relationship with the static load-carrying capacity of the composite laminate rectangular beam; under fatigue loading, the fatigue damage will first occur in the lower flange adhesive area of the whole composite laminate rectangular beam and ultimately result in the fracture failure of the entire structure. These results provide a theoretical reference and foundation for evaluating and predicting the fatigue performance of the blade main beam structure and even the full-size blade. [ABSTRACT FROM AUTHOR]