Simulation And Experimental Study On Vibration Parameter Identification Of Rotating Mistuned Bladed-Disk Based On Blade Tip Timing

The blade wheel system is an important part of large rotating equipment such as aero engines.Its working condition directly affects the safe and stable operation of the equipment,and the blade is prone to cracks and breaks during long-term work,which greatly reduces the blade work,The main reason for this phenomenon is blade vibration.Therefore,in order to avoid blade damage caused by blade vibration,extend the service life of equipment,and protect personnel safety,it is imperative to perform vibration measurement on rotating blades.This subject has carried out the identification simulation and experimental research of blade vibration parameters.The main research contents are as follows:(1)Using ANSYS finite element analysis software to perform modal analysis on the mistuned blade disk system.Because the blade disk system has speed up and speed down during the actual rotation,modal analysis is performed at different speeds and frequencies.Obtain the blade's dynamic frequency at different speeds,and fit the curve of blade's dynamic frequency with the speed and frequency,draw a Campbell diagram,and analyze the resonance region of the mistuned blade.(2)Establish a blade tip timing vibration measurement system model,obtain the blade stiffness through the blade dynamic frequency formula,and introduce this into the blade tip timing vibration measurement system model to make the simulation calculation results more realistic.Simulate and analyze the synchronous vibration signal of the impeller system under variable speed sweep and constant speed.Using the difference of the blade vibration displacement measured by the post-simulation sensor to identify the synchronous vibration parameters of the blades without rotating speed interphase sensor,the identification results are compared with the results of the blade vibration parameters obtained by simulation to verify the parameter identification of this type of rotating speedless phase sensor Identification accuracy of the algorithm.This identification algorithm can be used to identify the experimental parameters of blade vibration measurement.(3)Based on the principle of timing measurement of the blade tip,and aiming at the problem that the rotational speed interphase sensor is not easy to install,a vibration test bench without a rotational speed interphase sensor is set up to perform synchronous vibration measurement of the blade,and the measurement results are compared with the rotational speed interphase sensor.The comparison of the measurement results demonstrates the feasibility of the measurement method of the interphase sensor without speed,solves the problem that the interphase sensor is not easy to install in actual measurement,and proposes a more practical way for blade vibration measurement.