Spline Coupling Induced Nonsynchronous Rotor Vibrations

A mathematical model for predicting spline coupling induced nonsynchronous rotor vibrations is developed, and the predictions are compared with data from a rotor dynamics test rig. The special feature of the spline model is the characterization of the friction forces that are produced at the mating spline teeth surfaces and subsequent calculation of the internal damping coefficients. The spline internal damping and the resulting rotor instabilities are predicted for four different spline configurations and the solution results are correlated with measured data from a gas turbine rotor simulator test rig.