Reduced-Order Modeling for and Vibration Characteristics Analysis of a Hard-Coated Mistuned Blisk

Feng Gao,Wei Sun

doi:10.3390/coatings7070103

Abstract

This paper develops a damping strategy for the vibration reduction of a mistuned bladed disk (blisk) by depositing hard coating on its blades, and systematically investigates the vibration characteristics of the hard-coated mistuned (HCM) blisk. By using an improved fixed-interface component modal synthesis method (fixed-ICMSM), a reduced-order model (ROM) of the HCM blisk is established. Then, based on the proposed ROM, solutions of eigenvalue equations are carried out to obtain the natural frequencies and mode shapes. Further, modal loss factors and a damping matrix of the HCM blisk are achieved by taking advantage of the modal strain energy method and the proportional damping model, respectively. Moreover, the frequency response function of the HCM blisk, which can exhibit dynamic behaviors, was deduced. Finally, a mistuned blisk with a deposited NiCoCrAlY + YSZ hard coating on both sides of the blades is chosen as a study case to conduct a finite element analysis, and the results are compared with those obtained from the experimental test in terms of natural frequencies and mode shapes. The variation of the natural frequencies, the modal loss factors, and the frequency response function generated by the NiCoCrAlY + YSZ hard coating are studied, and the influence of coating area on damping capacity is further discussed.

Highlights

Due to the superior improvement of aerodynamic performance and structural design along with weight reduction, the application of bladed disks is widely increasing in aero-engines
NiCoCrAlY + YSZ hard coating on both sides of the blades is chosen as a study case to conduct a finite element analysis, and the results are compared with those obtained from the experimental test in terms of natural frequencies and mode shapes
Amistuned blisk made of aluminum and devices including an exciting hammer, a specific fixture, Amistuned blisk made of aluminum and devices including an exciting hammer, a specific a B&K-4517 acceleration transducer, a LMS16 front-end data acquisition controller (FEDAC, LMS, fixture, a B&K‐4517 acceleration transducer, a LMS16 front‐end data acquisition controller (FEDAC, Rouwen, Belgium), and a mobile workstation that had installed on it the LMS Test. lab, is shown

Summary

Introduction

Due to the superior improvement of aerodynamic performance and structural design along with weight reduction, the application of bladed disks (blisks) is widely increasing in aero-engines. In contrast with bladed disk assemblies, the single-piece-made structures bring about a significant problem in that the internal damping of the blisk decreases generally and enormously without a dovetail attachment root and friction interfaces, which can dissipate the vibratory energy straightforwardly [1]. Hard coating has been studied and employed widely by many researchers to improve surface performance, such as the wear resistance (or anti-friction resistance) generated by the increase of hardness [2,3,4], the increase of fatigue strength related to residual stresses [5], high-temperature resistance [6], and anti-corrosion [7] with nicer stability. The damping effect of hard coating, generated by the internal particle friction of coating material as illustrated in Figure 1 [8], was found and investigated gradually by many researchers [9,10,11], Coatings 2017, 7, 103; doi:10.3390/coatings7070103 www.mdpi.com/journal/coatings and has beeninused as1,the treatment for gradually vibration by control considerable prospects

Results

Discussion

Conclusion