Abstract

Although a bladed disk is typically designed to have identical blades, manufacturing tolerances, wear,
and other causes may cause random deviations among the blades. The blade-to-blade
discrepancies, denoted as mistuning, lead to vibratory responses mostly concentrated in small
regions of the bladed-disk assembly, according to a phenomenon called localization. The resulting
spatial confinement of the vibration energy causes the responses of some blades to become
dangerously high and increases the amplitude of the bladed-disk assembly's overall response. The
attendant increase in stresses can lead to premature high cycle fatigue (HCF) of the blades. In this study
we investigate whether vibration localization in a perfectly symmetric bladed disk assembly may
occur in the presence of nonlinearity. To this end, the nonlinear normal modes (NNMs) of a simplified
model of a bladed disk assembly are computed. The NNMs are then carefully examined to highlight
possible vibration localization phenomena.