Wear characterization under sliding–rolling contact using friction-induced vibration features

Skidding in rolling bearings often causes unexpected surface wear and early failures. Although vibration monitoring is widely used for bearing fault diagnosis, it is much less developed for wear analysis. This paper presents an investigation into characterizing the surface wear of a simplified sliding–rolling contact using friction-induced vibration features. The friction vibration mechanism under a rough sliding–rolling contact is explored by a mixed elastohydrodynamic lubrication model. It is found that the friction coefficient has a positive correlation with the surface roughness, which indicates that the friction behaviour can be used to track the wear state under the sliding–rolling contact. Furthermore, the vibration excited by different rough surfaces is studied experimentally on a roller–ring test rig. The friction-induced vibration signal is extracted and a feature parameter (K) is defined for quantitative wear characterization. Results show that the friction-induced vibration can well reflect the surface wear under the sliding–rolling contact. Compared with traditional time-domain parameters, the proposed parameter has a better linear relationship with the surface roughness.