Semi-analytical methodology to predict fretting damage areas in angular contact ball bearing raceways under variable loading
Cubillas D., Olave M., Llavori I., Ulacia I., Larrañaga J., Zurutuza A., Lopez A.
Small reciprocal movements in bearings can cause wear damage at the contact between the rolling elements and the raceway due to fretting phenomena. This damage is also called false brinelling or fretting corrosion, attending to lubrication conditions and causes vibrations and noisy operation, finally resulting in the need for the replacement of the component. Previous works from the literature have focused on experimental analyses of the damage and methodologies to simulate the occurrence of this phenomenon. These previous methodologies are centred on the effects of isolated fretting modes, such as radial fretting, rotational fretting and tangential fretting. However, the effects of external loads in angular bearings lead to high complex scenarios in which multiple fretting modes act simultaneously. In response to this demand, a novel methodology has been developed to analyse fretting damage as a consequence of the variable load and rolling motion. In addition, an analysis of the effects of each fretting mode is accomplished to determine the need to simulate both. The validation of the method is accomplished in two stages. First, a numerical validation through the finite element method (FEM) shows good agreement in the calculation of the contact reaction, the contact angle and tangential stresses, with relative differences under 5% and a considerable time reduction. Second, an experimental validation, which show a 16.1% mean relative difference between the damage areas and a 76% mean overlap of the damage areas.