Cyclic fatigue of composite airfoil structures

Progressive damage and fracture of a composite airfoil structure subjected to cyclic loading is evaluated via computational simulation. A computer model is utilized for the assessment of structural response, progressive fracture, and defect/damage tolerance characteristics. Critical locations for damage initiation are identified. Constituent material properties, stress and strain limits are scaled up to the structure level to evaluate the overall damage and fracture propagation for composites. Damage initiation, growth, accumulation, and propagation to fracture due to cyclic fatigue are included in the simulations. Results show the damage progression sequence and the changes in the structural response characteristics during different degradation stages. A procedure is outlined for use of computational simulation data in the assessment of damage tolerance, determination of sensitive parameters affecting fracture, and interpretation of experimental results with insight for design decisions.