On the fretting crack nucleation with provision for size effect

A thermodynamically based continuum damage mechanics (CDM) approach is employed as a propitious method for analyzing fretting crack nucleation. Intense fretting stress gradients in the contact region are examined and believed to be highly influential in the crack nucleation process. A methodology is proposed that allows for identification of an averaging zone as a function of the contact and loading parameters. The results predicted by this approach are verified by comparing the CDM crack nucleation predictions with the published experimental results on crack nucleation lives. Good agreement is observed between the predictions and the experiments.

► Fretting crack nucleation is analyzed using a thermodynamically based continuum damage mechanics.
► This approach obviates the need for definition of a critical crack size.
► An averaging zone with variable size is proposed to capture the size effect in fretting.
► The averaging zone is identified based on the analysis of stresses and their gradients.