Nevertheless, the vendor did not approve the fracture analysis report especially about the fatigue stresses. So the question rose whether the estimated stresses could impose fatigue crack propagation during 10 h or not. This manuscript attempted to simulate the crack propagation and fatigue life of the blades. The simulation has been done by numerical solution of exact model. Also, for initial rough estimation of fatigue life, a simplified analytic model has been used to calculate the stress intensity factors.
In both model the displacements and stress intensity factors were computed on the crack near the leading edge to calculate crack propagation trajectories and crack growth rate. The modified Paris model and FNK model have been used to estimate the fatigue crack growth rate.