Probabilistic Control Volume Method for Evaluating the Effects of Notch Size and Loading Type on Fatigue Life

The probabilistic control volume method has great prospects in correlating the effects of specimen size, notch and loading type on fatigue life or fatigue strength. In this work, the effects of notch size and loading type on fatigue life are investigated by using the probabilistic control volume method. Rotating bending and axial loading fatigue tests are at first performed on the hourglass specimen, circumferential V-notch specimen and V-notch plate specimen of 30CrMnSiA steel. Experimental results indicate that the notch reduces the fatigue strength of specimens in terms of nominal stress amplitude while in terms of local stress amplitude, the notch specimen could endure higher fatigue strength. Then, the probabilistic control volume method is used to evaluate the effects of notch size and loading type on fatigue life. It is shown that the probabilistic control volume method correlates well the effects of notch size and loading type on fatigue life, even for the local stress of the notch root exceeding the yield stress of the material.