A Multi-Scale Progressive Damage Model to Estimate the Fatigue Life of Wind Turbine Blades
Date
2024-06-18
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Abstract
Wind turbine blades experience fatigue loads resulting from cyclic loading conditions during its operation. Damage caused by fatigue loads poses a threat to the integrity of the wind turbine structure thus, it is critical to accurately predict the effect of damage progression on the remaining life of the blade. As it is the case with most composite material structures, a multiscale modelling approach is required when designing a fatigue methodology for wind turbines. Coupled models at different geometric scales have been used to understand how the operational response of the entire wind turbine system is affected by damage in the composite blades. However these methodologies employ high-fidelity damage models that are time and computationally intensive. Furthermore, most models that predict the blade’s lifetime rely on macroscopic damage models that do not consider the physical damage mechanisms. The macroscopic models produce a very conservative estimate of the fatigue life of the blades. Damage mechanics models which capture the stiffness degradation of the damaged blade in terms of a physical damage parameter such as matrix cracking can be incorporated within a multiscale framework. This type of model can capture the effects of the damaged blade on the entire wind turbine system to estimate the fatigue life with increased accuracy. This study aims to improve the current multiscale methodology by incorporating a damage mechanics model which accounts for matrix crack evolution under cyclic loading. The damage mechanics model implemented and presented in this thesis, is implemented based on a 2D finite element cross-section analysis in which the entire blade is modelled as a beam composed of several cross-sections. The material response and the structural response was analysed as damage progresses. This multiscale methodology which includes coupling with an aeroelastic analysis software, HAWC2, can be used to predict the structural response of the blades subjected to damage. The proposed method can also reduce the reliance on high-fidelity damage models to calculate the fatigue life due to damage, thus resulting in a more efficient approach.
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Keywords
composite materials, wind turbine blade, progressive damage, fatigue
Citation
Gunness, N. M. (2024). A multi-scale progressive damage model to estimate the fatigue life of wind turbine blades (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.