EFFECTS OF STATIC LOAD ON DYNAMIC STRUCTURAL-PROPERTIES IN A FLEXIBLESUPPORTED FOIL JOURNAL BEARING

This paper describes an experimental investigation into the structural dynamic characteristics of corrugated foil (bump foil) strips used in one type of compliant surface foil journal bearings and dampers. The nonrotating journal was supported by a compliant foil journal bearing and driven by two shakers which were used to simulate dynamic forces a cting on the bump foil strips. The dynamic structural stiffness and eq uivalent viscous damping coefficients were calculated based on the exp erimental measurements for a wide range of operating conditions. The r esults were compared to the analytical predictions obtained by a theor etical model developed earlier, and the agreement is considered reason ably well. Both experimental and theoretical results show that the dir ect structural stiffness and damping coefficients increase with increa sing bearing static load.