The results show that the fracture mode of blade is vibration fatigue and the main cause of initiation of fatigue crack is the mismatch between rabbet and tongue-and-groove.

• 结果表明,叶片的断裂模式为振动疲劳,叶片榫头与榫槽配合不当是萌生疲劳裂纹的主要原因。