## Abstract

The dispersion of rolling contact fatigue life is modelled assuming defects of uniform severity randomly distributed in the stressed volume. The probability of a defect occurring in a material volume is assumed to follow a Poisson distribution. The life N to failure at any defect is obtained as a deterministic function of a stress related hazard parameter t_{R} at the defect location. Defining equi-hazard contours as loci of constant hazard parameter, the area S_{A} enclosed by any equi-hazard contour is related to the hazard factor t_{R} at the contour through Hertzian analysis. A toroidal material volume bounded in each cross section by an equi-hazard contour with an identical hazard parameter value t_{R} contains all points at which a defect fails after a life not exceeding N. The probability S(N) of survival beyond N is equal to the Poisson probability P(0) that there is no defect within this volume and is obtained by transformation of P(0). It yields a three parameter Weibull distribution with a dispersion exponent β depending solely on the Hertzian stress distribution and presupposing no defect severity dispersion. It is estimated to be of the order β = 0.4-1.3, which reasonably coincides with the life dispersions obtained experimentally. The minimum life N_{0} can be set equal to the experimental value N = 0.05 N_{10}, where N_{10} is the 10% failure life quantile.

Original language | English (US) |
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Pages (from-to) | 147-154 |

Number of pages | 8 |

Journal | Wear |

Volume | 47 |

Issue number | 1 |

DOIs | |

State | Published - Mar 1978 |

## All Science Journal Classification (ASJC) codes

- Condensed Matter Physics
- Mechanics of Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry