Fatigue crack propagation simulation of airfoil section blade under aerodynamic and centrifugal loads

Cracks in aero-engine blades occur frequently due to high-cycle fatigue, which may cause accidents. Most of the existing studies simulating blade crack propagation are performed based on simplified blade shapes (rectangular, etc) or single loads (tension, bending, torsion, etc). These simplified treatments lead to a large deviation between the simulated crack propagation law and the actual blade propagation process. To fill the gap, the surface crack propagations of airfoil section blades under aerodynamic load, centrifugal load and the combined action of two loads are simulated based on the combined simulation of FRANC3D and ANSYS. The proposed method is verified by comparing the results with those obtained from the literature and experiment, respectively. In addition, the surface crack propagation path and the change of stress distribution during crack propagation under different loads are simulated. The results show that the crack propagates to the trailing edge (TE) and leading edge (LE) under aerodynamic load and centrifugal load, respectively. In addition, the cracks show three-dimensional shape characteristics under a single load. However, the crack propagates approximately along the plane under the combined action of two loads. The study can provide a theoretical basis for cracked blade failure analysis.