An Original DEM Bearing Model with Electromechanical Coupling

Abstract

We have developped an original 2D modeling of bearings by Discrete Element Method (DEM). The mechanical behavior and the dynamic of a bearing is well reproduced. An electromechanical coupling is introduced to provide monitoring solutions. In practice, the mechanical state in real-time is usually unknown and existing numerical methods are restricted. Electromechanical coupling seems to be able to indirectly measure the dynamic loading of the bearing. This behavior leads to the development of a new monitoring method based on electrical signatures. The study proposes an original method of simulating the bearings to correlate dynamic mechanical state with electrical responses, over time. The bearing is seen as a polydisperse granular chain where rolling elements and cage components interact with a Hertzian contact model. Moreover, rings (and housing) are also taken into account using a cohesive model. Indeed, while many studies have been conducted on bearing simulation using FEM and multibody approaches, this discrete approach gives relevant informations on physical phenomena in the contact interface. One of our objectives is to investigate the sensitivity of the electrical measurement due to typical mounting. The ability of DEM to describe accurately the mechanical state of a bearing has been established by means of a comparison with FEM, of load distributions in a static case. In dynamic, the consequences associated with the flexibility of the bearing mounting (rigid and elastic rings) are studied with mechanical stresses acting in rings and with the load distribution. Also, by accessing dynamic stresses, this modeling opens certain possibilities on studies of damage and wear by providing the history of contact.