Modal and transient analysis of a rotating multi-packet blade system with a mistuned blade

Abstract

A rotating multi-packet blades system designed to be cyclically periodic are widely used in engineering fields. These rotating structures consist of several blades attached to a disk and shrouds. Since the disk and the shroud of the structures possess flexibilities, disk and shroud cause coupling effects between blades. In general, there always exists small and unexpected discrepancy among blades due to manufacturing tolerance, operation wear and environmental change. This is called mistuning system which may cause an unexpected significant increase of responses of some blades. The increase of stress in blades causes to fatigue of the system. If the multi-packet blade system includes a mistuned blade, vibration energy is often concentrated to some blades. This is called the vibration localization of the mistuned system. In order to avoid unexpected vibration localization phenomena of the system, the effect of mistuned blade should be investigated thoroughly. In this study, modal and transient characteristics of a rotating multi-packet blade system with a mistuned blade are investigated.