The non-linear behaviour of rub-impact systems have been studied recentlyby approximating rotor-stator systems as rubbing cylinders. In reality, therotor shape is more complex, resulting in richer dynamics over smaller parameter ranges. In this paper, a bladed turbine is modelled using a Jeffcott rotor with three rigid beams attached to the mass center. The contact forces are described by a radial restoring force induced by the massless outer ring, and a tangential Coulomb frictional force. The results are presented in bifurcation diagrams and compared with a previous model described by three flexible beams entering in contact with a fixed ring assuming large displacement beam theory. This paper shows that the two models described give similarities in the overall bifurcation diagram, only showing greater differences in localized frequency ranges.
Godkänd; 2012; 20121217 (flothi); Konferensartikel i tidskrift