Nonlinear vibration analysis of a rotor system with parallel and angular misalignments under uncertainty via a Legendre collocation approach

In this paper, the propagation of bounded uncertainties in the dynamic response of a misaligned rotor is investigated using a Legendre collocation based non-intrusive analysis method. A finite element rotor model is used and the parallel and angular misalignments are modelled by additions of stiffness and force terms to the system. A simplex meta-model for the harmonic solutions of the vibration problem is constructed to take into account the uncertainties. The influences of uncertainties in the fault parameters are analysed and the calculation performance of the interval method is validated. Different propagation mechanisms of the uncertainties are observed in the interval responses and discussed in case studies. The results of this study will promote the understandings of the nonlinear vibrations in misaligned rotor systems with interval variables.