Analysis And Experimental Study On Vibration Characteristics Of Rotating Mistuned Bladed-disk System

Blade is an important part of aero-engine,gas turbine and large compressor.When it works at high speed,the influence of blade life and reliability on engine is great.Due to errors in the manufacturing process,there will be wear in use,so that there is a small difference in the properties between the blades,this small change is called the detuning of the blade.It is precisely because detuning is an objective phenomenon that the modal and vibration characteristics of the blade-wheel disk structure will be greatly affected.In general,the blade wheel structure after detuning,the blade amplitude and response increase,the blade will appear local damage.Light causes navigation Air engine or gas turbine mechanical vibration becomes larger,serious will cause a blade fatigue damage ahead of time.So it is very important to analyze the vibration characteristics of blade-wheel disk system.This paper focuses on the vibration characteristic analysis of rotating detuning blade-roulette wheel system.(1)By establishing strong coupling,weak coupling and general coupling finite element model,direct method,mobile interface CMS super-unit method and fixed interface CMS super-unit method are used to simulate the vibration of detuned disk system with different degree of coupling,and the influence of coupling degree of different blade-roulette wheel on the vibration localization of detuned disk system is discussed.By contrast,we find a more suitable method for analyzing the vibration characteristics of the detuned disc structure with any degree of coupling.(2)Based on the mobile interface CMS super-unit method,the vibration response of the rotating detuned blade disc system is studied.The vibration response value,vibration response waterfall diagram and vibration response mode diagram of weakly coupled detuned blade disc and strongly coupled detuned blade disc are analyzed.(3)Non-contact measurement of the vibration of the rotating detuning blade is carried out using the existing experimental bench,and the vibration signal is reconstructed by the improved parameter identification method to verify the reliability of the finite element method.