Nonlinear Vibration Analysis of a Flexible Rotor Supported by the Full-Circular Journal Bearing (Numerical Analysis Using the Shooting Method under the Half Sommerfeld Boundary Condition)

Abstract

This study investigates the nonlinear vibration of the flexible rotor supported by the full-circular journal bearing. The numerical simulation method, so called shooting method, is utilized to investigate both stable and unstable solutions. Both the synchronous and asynchronous vibrations are analyzed. Because the shooting method is available only for the periodic solution, the investigation of the asynchronous vibration is performed only for the case without unbalance of the rotor system. The dynamical characteristics of the asynchronous vibration, such as its occurrence range and shape of branches including stable and unstable solutions, are clarified. Also, the influences of viscosity and stiffness ratio between the shaft and bearing on the dynamical characteristics of the asynchronous vibration are explained.