Micropitting Modelling in Rolling–Sliding Contacts: Application to Rolling Bearings

Abstract

In this article an engineering approach is described to model micropitting in rolling-sliding, heavily loaded lubricated contacts. The competitive mechanism between surface fatigue and mild wear is captured in the present approach as well as the effects of deterministic surface microgeometry (e.g., roughness). The fatigue model is based on the Dang Van fatigue criterion and the mild wear model uses a modified Archard approach. The complete modeling scheme is validated experimentally first using laboratory-controlled conditions, where the surface topography is varied as well as the operating conditions in the contact. Then the model is applied to describe the behavior of full-bearing tests. The behavior of the model agrees well with the experimental observations, qualitatively.

Generation of wear particles in lubricated contcats during running-in

“…They observed a good agreement with the experimental data in the prediction of the size of micro-pits [89] and the topography evolution [91]. In their approach the evolution of the surfaces in time could be simulated.…”

“…Morales-Espejel et al [89,90] combined a cumulative damage model and a local Archard wear equation to simulate the generation of micro-pits. They observed a good agreement with the experimental data in the prediction of the size of micro-pits [89] and the topography evolution [91].…”

A Model for Rolling Bearing Life with Surface and Subsurface Survival—Tribological Effects

“…In the current formulation, the treatment of the surface stresses and damage can be accomplished by using an advanced surface distress model for elastohydrodynamically lubricated (EHL) rolling-sliding rough contacts developed by MoralesEspejel and Brizmer (18); further description of this model is given below.…”

“…Tribological models can be used to derive these damage functions. When several mechanisms are present-for example, surface distress and mild wear-the damage function should account for possible competitive mechanisms (Morales-Espejel and Brizmer (18)) and the statistical treatment should follow (McCool (32)). As an example of surface fatigue (Lubrecht,et al (33)), the following damage function is considered:…”

“…Because of this, there is an increased need for more versatile or generalized rolling bearing life models, able to adapt and incorporate new developed knowledge about the tribology of surface initiated failures of the rolling contact. Despite the progress achieved in the last few years in the numerical modeling of the tribology and surface performance of rolling contacts (e.g., Epstein,et al (16), (17); Morales-Espejel and Brizmer (18); Morales-Espejel and Gabelli (19); Brizmer, et al (20); Warhadpande and Sadeghi (21)), the integration of this new knowledge into an engineering model for bearing life estimation is, to some extent, hindered by the simplicity of present standardized life rating formulation (ISO 281:2007 (15)), which only relies on averaged global de-rating factors. This approach, although sufficient for most common situations, is not designed to give an account and differentiate among surface/subsurface competing failure modes that may occur in a bearing when exposed to a hostile environment and tough operating conditions.…”