A Mathematical Model of Spalling Fatigue Failure in Rolling Contact

Abstract

Variables affecting the fatigue life of a rolling contact are identified. A mathematical model of sub-surface and surface crack propagation is presented. The life to failure of volume elements in the vicinity of a defect (defect life) is formulated. A term “severity” of a microdefect has been defined. The model is characterized by the inclusion of bulk material parameters, defect characteristics and parameters of geometry, stress, lubrication and surface topography. A statistical expression for the life of an entire rolling body is based on the defect life formula. The new model comprises current standard bearing life prediction formulas as a special case.