Coupled forms of vibrations in rotating machinery

The paper contains a study of mutual interactions, which occur between lateral, torsional and axial vibrations in multi-supported rotors operating in the non-linear range. The methods of modelling of the selected defects have been presented (e.g. rotor cracs and bearings misalignments). These defects have been regarded as the factors generating the coupled forms of vibrations. In the paper a part of work devoted to the influence of circumferential location of the cracs and kinetostatic and dynamic rotor deflection line on the system dynamical response has been presented. Applicability of coupled and phase vibration spectra analysis in diagnostics of such kind of defects has been indicated. Coupled forms of vibration are generally a results of different kinds of couplings taking place in the system and interactions between construction and material imperfections. Presented here as example can be rotor cracs and misalignment of the rotor line.