Quantitative fatigue limit prediction of mechanically long crack under mixed modes based on fracture mechanics and fatigue mechanism

To predict the fatigue limit with a mechanically long crack under mixed modes based on the fracture mechanics, fatigue tests were conducted with an inclined notch. As a result, damage accumulation (DA) mode of fatigue crack propagation was found to occur from the crack tip. The DA mode is caused by the formation and coa-lescence of micro-voids. Therefore, the method of modifying the initial crack length by considering the DA mode crack propagation length has shown potential application in fatigue limit prediction. Moreover, a classification method of DA and normal modes is proposed.

Automated summary

This study conducted fatigue tests with an inclined notch to predict the fatigue limit of a mechanically long crack under mixed modes based on fracture mechanics. It was found that the damage accumulation (DA) mode of fatigue crack propagation occurred from the crack tip, caused by the formation and coalescence of micro-voids. Therefore, the method of modifying the initial crack length considering the DA mode crack propagation length showed potential application in fatigue limit prediction. Additionally, a classification method of DA and normal modes was proposed.