在进行振动疲劳试验时，复合材料出口导流叶片包边处出现裂纹，且叶片固有频率下降超过15%。采用宏观观察、金相检验、扫描电镜分析等方法，对叶片包边裂纹的产生及固有频率下降的原因进行了分析。结果表明：叶片包边发生了疲劳开裂，原因是叶片局部受力、变形不均匀，包边表面的圆弧形划痕促进了裂纹的萌生及扩展；叶片与树脂纤维界面的黏接强度较低，导致了桨根R区发生层间开裂，从而导致叶片固有频率下降。

During the vibration fatigue test, the edge of the composite material outlet guide blade cracked, and the natural frequency of the blade decreased by more than 15%. The causes of blade edge cracks and the decrease in natural frequency were analyzed using methods such as macroscopic observation, metallographic examination and scanning electron microscopy analysis. The results shows that fatigue cracking occurred on the edge of the blade, which was due to uneven stress and deformation in the local area of the blade. The arc shaped scratches on the surface of the edge promoted the initiation and propagation of cracks. The bonding strength between the blade and resin fiber interface was low, leading to interlayer cracking in the R zone of the blade root, resulting in a decrease in the natural frequency of the blade.