EFFECTS OF MEMBRANE STRESSES IN THE PREDICTION OF FOIL BEARING PERFORMANCE

The effects of membrane stresses which result from both viscous drag and the three-dimensional structure of an incompressible journal foil bearing are discussed. The structural model includes combined bending, membrane, and elastic foundation effects. The pressure in the lubricant film is predicted using an incompressible Reynolds equation. Finite element methods are used to predict both the structural deflections and the pressures in the lubricant film. Results will demonstrate that membrane effects are significant in an elastically supported foil bearing where elastic foundation effects are normally considered to provide the primary resistance to deflection. The effects of viscous drag are small but not insignificant.