IDENTIFICATION OF UNBALANCE CHANGE USING A NONLINEAR MATHEMATICAL-MODEL FOR MULTI-BEARING ROTOR SYSTEMS

A consideration is provided of the possibility of identifying changes in the residual unbalance of a multi-bearing rotor system. It is assumed that the relative motion of the rotor journals with respect to the bearings can be measured before and after the change in unbalance take place. Furthermore, it is assumed that a non-linear mathematical model of the system is available. If one can assume that the change in the system response is due to the change in unbalance at one plane of the rotor only (e.g., a few blades from one row of a turbogenerator are lost), the paper offers a method for the identification of that plane as well as the magnitude of the required correcting weight. © 1994 Academic Press Limited.