Probabilistic rolling contact fatigue approaches with a loading level relevance

Optimal rolling contact fatigue (RCF) tests try better to cover possible production loading range. And probabilistic RCF approaches are developed with an implicit consideration of the loading level relevance. In accordance with the bearing RCF parameters Pr and Cr in the code ISO281, a new parameter, i.e. equivalent dynamic radial load intensity factor Kr (=Pr/Cr), is applied for describing bearing synthetic RCF condition. A two parameter power exponential equation is applied for describing the Kr relevant exponent of Lundberg and Palmgren (L-P) qualitative formula. Three-parameter Weibull (3-PW) distribution is proved to be an appropriate model to describing the present test exponent data. Probabilistic approaches considering the Kr relevance are then developed for bearing RCF life prediction and design parameter determination. Two probabilistic measurements of failure/survival probability (F/P) and confidence (C) are included by the present approaches.