Abstract
In present study, a new frequency domain method, without parameter estimation, is proposed to identify unbalance of nonlinear rotor system. The nonlinearity of the rotor system is mostly produced by the journal bearing. Previous work paid too much attention to the bearing parameters estimation, which is not necessary for unbalance identification. In the new algorithm, forces related to those bearing nonlinear parameters are all coupled into one term, the oil film force. This term is nonlinear but it is closed to periodic. The process of calculation and the condition of the equation solving has been presented.
In order to test this new algorithm, numerical simulation has been taken. At the beginning of the numerical simulation, the nonlinearity of rotor system supported by journal bearing has been studied. Finally, the method has been applied in practice. Rotor system response after balancing has been reduced to a low level. The proposed method is testified to be applicable.
Key words: Nonlinear rotor system Unbalances Identification