Abstract
Recently, in Lundberg-Palmgren theory pertaining to the rating life and load rating of rolling bearings, it was found that a P-S-N (Probabilistic Stress-life) curve for the structural fatigue has not been established and an imperfect product law of probabilities without a minimum life in the Weibull life theory has been applied considering as the Weibull slope depends on the strength of materials. Therefore, the Lundberg-Palmgren theory has included various questions. In accordance with the published rolling bearing theories since the Lundberg-Palmgren era till present these questions are summarized. Further, the P-S-N curve and size effect as well as their application principles are discussed.
