6. Inclusion of the Impact of an Unbalanced Rotor

Chapter 5 presented the calculations for the rotating shaft, but without residual unbalance. In practice, however, there is a residual unbalance in the rotor of every rotating machine because it is impossible to balance the rotor perfectly. The residual unbalance must be included in the calculation. This chapter presents the influence of the rotating shaft with residual unbalance on the determination of the stiffness, damping and mass coefficients. As in the previous chapter, the calculations were made on the basis of the signal generated by the numerical model built in the Samcef Rotors software. The chapter also presents the way the error changes in the calculation of the stiffness, damping and mass coefficients, both with the unbalance and when its effect is leveled out. Some of the results in this chapter are also presented elsewhere (Breńkacz 2015b).