1. Determining the characteristics of rotor elements

The basic elements of a rotor are disc, shaft and bearing. Unbalance, which cannot be completely avoided, must also be taken into account. Expressions of kinetic energy are needed to characterize the disk, shaft and unbalance. The deformation energy is needed to characterize the shaft. The expression of the virtual work of the forces due to the bearings enables us to determine the generalized forces . The general equations of motion of a rotor are obtained from the following steps:

• the kinetic energy T, the deformation energy U and the virtual work of external forces δ W are calculated for all elements of the system;...