It is one of the most fundamental steps to clarify the parameters of the initial distribution of structural member's fatigue life, whenever the reliability of any structure is analized using the reliability theory. Whittaker and others reported some studies on fatigue life distributions accepting the Weibull distribution with two parameters but without the location parameter.
However, the Weibull distribution with three parameters including the location parameter should be considered as the distribution function at a stress level near the fatigue limit of a material. Since structures are designed often based on the fatigue limit of the members, it is important for the reliability analysis of the structures to clarify the fatigue life distribution at such stress levels.
From the above viewpoint, the estimation of three parameters of the Weibull distribution was made in this study by means of several methods. Before the estimation was performed, Monte Carlo technique was applied to prepare many experimental data of fatigue life governed by the Weibull distribution with three known parameters. Then the values of each parameter estimated by several methods were compared with the true values given in advance, and the applicability of these estimating methods was examined. Furthermore, the sample size necessary to estimate the parameters of the initial distribution was discussed quantitatively.
