ROLLING CONTACT MODELING IN ABAQUS

I attended University of Florida for my graduate studies. My PhD research was based on investigation of Rolling Contact Fatigue (RCF) in aerospace bearings using finite element analysis. RCF is responsible for failure of bearings in many critical aerospace applications. Therefore , in-depth investigation of stress fields induced during RCF is topic of great interest in bearing/aerospace community.  The objective of this project was to study the complex stress fields induced in bearings under the Rolling Contact Fatigue loading. For this study a 2D rolling contact was simulated using Abaqus/CAE. Simulation involves a circular rod (at center) which is radially loaded by 3 balls (See. Fig 1a). Rotation of the center rod under radial loading induces complex RCF stresses in the vicinity of contacting region (See Fig.1b). Two complete revolutions of the central rod are simulated. One can easily see how stresses are induced along the circumference of rod as it rotates relative to 3 balls (See the video for better illustration. Link to video is given below). Such location in the vicinity of contacting region is usually the location where failures initiate.  The failure process is accelerated by presence of impurities, inclusions and other micro-structucral features present in the material. To understand this better, a circular carbide particle (a type of inclusion in many materials) is considered as an example. Carbides are usually order of magnitude smaller compared to bearing dimensions. Therefore, to model such "micro"-structural features, a multi-scale modeling approach is required. This is achieved by using submodeling technique available in Abaqus. This technique allows user to zoom into small region of interest and study it with well-refined mesh (See Fig 1c). Because of a mismatch in properties of carbides and surrounding material, stress concentration is observed as seen in Fig.2. Such stress concentration accelerates the failure process and is usually the location of crack nucleation. For better visualization, please visit the following link that depicts this process better. https://www.youtube.com/watch?v=OIbiEMtmqMQ