Numerical analysis of viscous lubricating oil penetrating into a three-dimensional rolling contact fatigue crack

The penetration of a viscous lubricating oil into a three-dimensional surface crack under a rolling contact stress was calculated. The finite element method was applied to solve the Reynolds equation coupled with the elastic deformation of the crack. The process of penetration is roughly the same as in the two-dimensional model. The lubricating oil begin to flow into the crack when the contact pressure passes the crack mouth. The lubricating oil enters the crack tip and increases the stress intensity factor when nondimensional viscosity beta = etanuE(2)/(ap(0)(3)) is small. The crack is not open when beta is large, because the contact pressure passes before the lubricating oil flows into the crack. The critical value of beta was calculated. The penetration of the lubricating oil in the three-dimensional model is not easy as compared with the two-dimensional model.