Model-based malfunction identification from bearing measurements

Some results of a model based malfunction identification procedure, which uses the vibration measurements taken in the bearings only of a rotor system, are presented. The procedure has been applied to experimental results obtained on a 4 oil film bearing, 2 rigidly coupled shafts test rig, on which several different malfunctions have been applied. The Ix rev. vibration components are related to Ix rev. excitations (unbalance, bow and coupling misalignment) and the 2x rev, vibration components to 2x rev. excitations (transverse crack, journal ovalization, axial unsymmetry). The results allow to evaluate the accuracy of the method and the capability of distinguishing among different faults which generate similar effects, and its sensitivity to measuring or modelling errors.