Vibration reduction of the blisk by damping hard coating and its intentional mistuning design

This paper presents a vibration reduction approach of the blisk by using of the damping hard coating and its intentional mistuning design. Firstly the amplified forced vibration responses of mistuned blisk were studied based on the reduced order finite element model (FEM) established by component mode synthesis (CMS) method, by using the actual mistuning value of a blisk specimen. Then the effects of damping hard coating on forced vibration responses of the tuned and mistuned blisk were investigated. Further, intentional mistuning design by depositing hard coating with different thickness on blades was researched, after comparing several mistuning patterns. At last, experiment research was conducted by using a blisk specimen with random mistuning. NiCrAlY coating was deposited on blades with designed thickness, in accordance with the simulation results. It reveals to be an effective approach for reducing the vibration level of mistuned blisk, judging from the observed lower vibration response level after the intentional mistuning design by hard coating. The results of this paper can help to decrease the fatigue failure induced by mistuned vibration and improve the structure integrity and security of the blisk in aero-engine. (C) 2018 Elsevier Masson SAS. All rights reserved.