A Note on Blade Loss Dynamics of Rotor-Bearing Systems

Abstract

The equations for a single-mass rotor are examined for maximum response following an impact load created by a blade loss. The close examination of the undamped system gives insight and understanding to the dynamic response of the rotor system during an actual blade loss. The time transient response orbits for the single-mass system are presented for operation below, coincident with and above the given natural frequency. The orbits clearly indicate the ratio of maximum response relative to steady-state (i.e., overshoot ratio). The results of the influence of various damping ratios on the transient response peak amplitude are presented in dimensionless form. The blade loss transient response of a three bearing, eighteen-degree-of-freedom rotor system is presented to illustrate the validity of the basic concepts developed in the single-mass rotor analysis.