A LCF(Low Cycle Fatigue)Life prediction method is provided on the basis of systematic experimental investigation

in which the median and reliability LCF Lives to crack initiation for the bolt holes of rotating disk can be predicted precisely by statistic data of smooth round bar specimen LCF lives to failure. The study shows that the LCF life to crack initiation for bolt holes of disk usually depends on the maximum strain history appliod to the critical points of the bolt holes

and the strain gradient influence on the LCF life to crack initiation can be neglected as usual. In addition

the study also indicates that the median LCF life usually depends on the steel chemical composition and its thermal treatment.