Predicting white etching matter formation in bearing steels using a fretting damage parameter

Abstract White etching cracks (WECs) are deleterious artifacts found in fatigue damaged bearings. The formation of WECs has been attributed to the frictional energy dissipation at subsurface cracks during cyclic rolling contact. This study introduces a novel Ruiz fretting damage parameter (FDP) implementation to predict the frictional energy dissipation at subsurface cracks. A parametric study using a finite element model explores the role of crack length, orientation, depth, and coefficient of friction (COF) on FDP. The FDP is maximized at a normalized length of 0.50a and depth of 0.78a, between the orientation of ± 30°, at a COF of μ = 0.3, in agreement with experimental observations. These results provide strong evidence of the FDP as a predictor of WEC formation.