Statistical Reproducibility of the Dynamic and Static Fatigue Experiments.

Abstract

The number of test samples used to characterize the fatigue constants needed for failure predictions for ceramic materials determines the confidence in these predictions. The statistical reproducibility of the dynamic and static fatigue experiments used to measure the fatigue constants was analyzed using both statistical theory and a Monte Carlo computer simulation technique. It was found that the statistical reproducibility depended not only on the number of test samples but also on the other experimental test variables. It was shown that the uncertainty in the statistical reproducibility can be large especially for sample size less than about 100. Guidelines for selecting the optimum sample size for a given dynamic or static fatigue experiment are given. It is recommended that before meaningful conclusions can be drawn regarding the effect of a test variable on fatigue, the statistical reproducibility of the experiment be determined. (Author)