Failure prognosis of rolling element bearings (REBs) is crucial in rotating machinery PHM. The damage evolution in REBs consists of two main phases: damage initiation and propagation. The conventional REB life models address the lifetime of the bearing to the damage initiation, i.e. first defect formation [1]. However, after the first defect formation, the bearing might be fully operational for millions of cycles. After the first defect formation, it propagates in the circumferential direction of the raceway, until the bearing becomes non-operational [2]. Many diagnostic tools have been developed in order to monitor the defect propagation, in contrast to prognostic tools which are still lacking. In order to build an efficient and accurate prognostic tool, the damage mechanism during the propagation phase must be understood. For this purpose, a physics-based model of a spalled bearing has been developed. The model aims to study the material behavior at the trailing edge of the spall during the rolling element (RE) impact. It integrates a non-linear dynamic [3] and finite element (FE) models. The dynamic model adds insights regarding the dynamic response of a faulty bearing. However, this model cannot provide information regarding the damage accumulation as a result of RE-spall edge interaction. Thus, the results of the dynamic model are used as an input to the FE model. A qualitative damage analysis for crack evolution within the spall edge was conducted. Moreover, a metallurgical analysis of the bearing from endurance tests was carried out. The metallurgical analysis added insights regarding the damage mechanism and was used for model validation. The results achieved from the damage analysis are in good agreement with the experimental observations. To our best knowledge, this is the first study attempting to simulate damage evolution within the spall edge based on physical insight.

Keywords:

Rolling elements bearing, non-linear dynamic modeling, finite element modeling, spall propagation

Reference

[1] Sadeghi, F., Jalalahmadi, B., Slack, T.S., Raje, N. and Arakere, N.K., 2009. A review of rolling contact fatigue. Journal of tribology, 131(4), p.041403.

[2] Rosado, L., Forster, N.H., Thompson, K.L. and Cooke, J.W., 2009. Rolling contact fatigue life and spall propagation of AISI M50, M50NiL, and AISI 52100, Part I: experimental results. Tribology Transactions, 53(1), pp.29-41.

Kogan, G., Bortman, J. and Klein, R., 2017. A new model for spall-rolling-element interaction. Nonlinear Dynamics, 87(1), pp.219-236.