The use of microcontact pressure statistics in fatigue life modeling of rolling contacts

摘要

Modern rolling contact fatigue life models generally use localized stresses or stress intensity factors at discrete defects or in asperity contacts as the parameter for predicting volume element survival probability. Some models (Ioannides-Harris 1985) predict volume element survival directly from local stress; a second approach (Chiu-Tallian-McCool 1971, Tallian l993a, b, 1996a) uses macro-stresses multiplied by a defect severity factor and a third approach (Keer 1983, Blake et al 1991a, b, 1994, Kudish 2000) employs stress intensity factors calculated for each defect. This Note addresses a difficulty of the statistical approach as applied to asperity contacts, and calls attention to recent published developments that may overcome it. The asperity contact case is practically important, since asperity contacts are controllable through engineering parameters (load, speed, lubrication, surface finishing) and their effect on life is substantial in a large proportion of practical applications. Asperity statistics are also furthest advanced of all defect distribution statistics in rolling contact technology.