Curve Veering in the Eigenvalue Problem of Rotor-Bearing Systems

Abstract

When the eigenvalues approach each other as system parameters vary, they often cross (curve cross) or abruptly veering (curve veering). An important characteristic of the curve veering in the eigenvalue problem is that the mode shapes associated with eigenvalues before veering are abruptly change during veering in a rapid but continuous way. In this paper, the existence of the curve veering in the eigenvalue problem of general rotor-bearing systems including the effects of rotary inertia and gyroscopic moments is verified by modal analysis and perturbation technique. The criteria of the curve veering are derived as bearing stiffness and rotational speed vary. The abrupt but continuous changes of mode shapes during veering are also illustrated.