Procedure and results of investigation of crack initiation under fretting fatigue

Technique for determination of crack initiation lifetime under fretting fatigue has developed. It represents a combination of the French’s method and the statistical staircase method. Using this technique, relation between crack initiation and total lifetime for pair of steel 15 kp – steel 45 under fretting fatigue established. Fatigue crack initiation part constitutes about 50 per cent when total lifetime is equal to ~ 106 cycles. Lowering stress amplitude down to fretting fatigue limit leads to increasing the fatigue crack initiation part