Failure prognosis of the rolling element bearings (REBs) is crucial in the rotating machinery. The damage evolution in the 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. However, after the first defect formation, the bearing might be fully operational for millions of cycles. There has been a growing awareness of the need to understand the damage mechanism during the propagation phase. Over the past two decades, studies attempting to understand the damage mechanism and to develop damage propagation models have been published. Nevertheless, the damage mechanism is only partially understood, the existing models are inefficient and the physical phenomena are not well represented. Once the damage mechanism is understood a physics-based prognostic tool can be developed. In order to understand the spall propagation phase, a physics-based model has been developed. The model aims to study the material behavior at the trailing edge of the spall during the rolling element (RE) impact. Based on the model results 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.
