The Applicability of the Floating-Frame Based Component Mode Synthesis to High-Speed Rotors Available to Purchase

The floating frame of reference formulation (FFRF) together with modal reduction is a standard method in multibody system dynamics. As an advantage of the FFRF, fully nonlinear coupling of small flexible deformations superimposed to arbitrarily large rigid body motion is considered. The idea of the present paper is to apply the FFRF with component mode synthesis to an electromagnetically levitated high-speed rotor, in which large tilting angles may occur, which are not accounted for in classical rotor dynamics. The applicability of FFRF to rotor dynamics, especially close to bending resonance, is not studied in detail in the literature. Thus, fully nonlinear and transient finite element computations are compared to different FFRF-based simulations. In exhaustive numerical studies of a flexible two-disc rotor, comparing FFRF and fully nonlinear transient computations, it is shown that the choice of reference frames and the rotation parameterization influence accuracy of results and CPU-performance.