Bearing Test Rig Dynamics Problem Identification And Model Tuning
Swanson, E.E., Kirk, R.G., 1999
Proc. IMAC XVII, SEM, pp. 270-276.
The experimental determination of the dynamic stiffness and damping for fluid-film bearings and seals is an increasingly important research subject in the area of rotating machinery design. During development testing of a new test rig for dynamic characterization of oil lubricated, hydrodynamic bearings, unexpected phase shifts in measured shaft response data were observed. This paper describes the problem that was observed and the ensuing experimental modal investigation of the shaft dynamics. Both traditional impact and scanning doppler laser velocimeter techniques were used to develop a tuned rotor dynamic model which was subsequently used to help understand and explain the unexpected phase shift observations. The results from this analytical study highlight several design issues which should be considered in future test rig designs to avoid similar difficulties.