LCF-HCF strain–life model: Statistical distribution and design curves based on the maximum likelihood principle

In the paper, the statistical distribution of the total strain and the fatigue life in the low cycle fatigue (LCF)–high cycle fatigue (HCF) life range is analytically derived starting from the Coffin–Manson and Morrow model. The maximum likelihood principle is exploited for parameter estimation, thus allowing to consider both failures and runout specimens. A straightforward procedure for the estimation of the design curves based on the likelihood ratio confidence lower bound has been also developed. The proposed model has been validated with literature datasets obtained by testing steel and aluminum alloys, proving its effectiveness and representing a reliable alternative to the currently adopted literature models.