Engineering

Statistics

Materials science

Bending

Distribution (mathematics)

Weibull modulus

Shape parameter

Mathematics

Mathematical analysis

Weibull distribution

Structural engineering

Fatigue limit

Maximum likelihood

International Journal of Fatigue

This paper presents proposed characteristics of the S-N curve using the 2 and 3-parameter Weibull distribution for fatigue limit and limited life respectively. The parameters of the proposed model are estimated using the maximum likelihood method. Additionally, it has presented a method to estimate initial values for the likelihood function. Two applications are presented, whose S-N curves were characterized by using the results for rotary bending of S355J2 + C and C45 + C steels. The proposed S-N curves can be used to determine the fatigue life for low probability of failure, e.g. 1%, which is not recommended by ASTM E-739–91, when using a normal distribution.

Determination of fatigue life for low probability of failure for different stress levels using 3-parameter Weibull distribution