Flexibility matrix method applied to the finite element elastohydrodynamic analysis of plain journal bearings

Abstract

The main reasons for using the finite element method (FEM) in the analysis of fluid film bearings are its flexibility in handling complex configurations, and particular boundary conditions, and the ease of its coupling with a structural finite element analysis to produce an elastohydrodynamic (EHD) solution. In this work an approach based on combining separate hydrodynamic and structural analyses is followed by introducing the structural information into a modular code in the form of an externally calculated flexibility matrix. In order to study a wide range of bearing housing and shaft configurations, a semi-automatic numerical procedure has been developed involving the use of commercial and in-house codes making it possible to use different grids for FEM hydrodynamic and elastic analyses, with higher computational efficiency with respect to uniform grids. The final pressure distribution and bearing deformed geometry are then obtained by an iterative calculation. Some results are reported for different bearing configurations.