Control of mistuning level using hard coating for blisks based on mistuning identification technique

Mistuning will lead to vibration localization of blisk, which seriously affects the service life of blisks. To control the mistuning level of blisks, a novel control method using hard coating is proposed. In this method, the thickness of hard coating is designed according to mistuning state of blisk substrate, so that, the mistuning level can be controlled and the vibration localization can be reduced in the designed coated blisk. Herein, the identification technique based on component mode mistuning (CMM) reduced-order model is improved to calculate the mistuning of blisk substrate and mistuning adjustment of coatings with different thicknesses. Based on the premise that the influences of the mass, stiffness and damping mistuning on the coated blisk response are all considered, a reduced-order model of the coated blisk is established, which includes the blisk substrate mistuning and the coating mistuning adjustment. It is rare to consider so many kinds of mistuning in previous studies. Based on this model, the function of coating thickness and coated blade response is obtained by the polynomial function fitting technique. Then, coating thicknesses can be determined with the target that the responses of each coated blade are equal. The first and second bending responses of the numerical and actual cases before and after coating are compared to verify the effectiveness of this method. It is found that the localization response amplitude is reduced significantly, and the mistuning level is effectively controlled. (C) 2021 Elsevier Masson SAS. All rights reserved.

Automated summary

A novel control method using hard coating is proposed to control the mistuning level of blisks, where the thickness of the hard coating is designed according to the mistuning state of blisk substrate. The method effectively reduces vibration localization and controls mistuning levels in the designed coated blisks.