The Effects of Nonlinear Bearings, Gyroscopic moment and Dependency of Stiffness and Damping Coefficients on Viibration Analysis of rotor systems

The nonlinearity effects of oil film in bearings, gyroscopic effect, dependency of stiffness and damping coefficients on frequency are considered in modeling and vibration analysis of rotor systems. Once a computerized program is written based on finite element method. In this method four element types including element of shaft, disk, bearing and suspension are applied. The responses of systems are obtained based on linear theory and then, the program applies nonlinear effects and nonlinear model is also analyzed. Then linear and nonlinear responses of the system are compared with each other and also with the results of other papers. Separately gyroscopic damping and its effect in vibration analysis is investigated. Ultimately conclusions are presented.

Keywords:

Rotor vibration , Nonlinear bearings , Gyroscopic effect , Finite element method