Reliability And Dynamic Stiffness Analysis Of Aero-engine Bearing

The development of aviation industry reflects the strength of a country in science and technology,industry and national defense.The aero-engine is a highly complex and precise thermal machine,which not only provides the power for the aircraft to fly,but also affects the performance,reliability and economy of the aircraft directly.As an indispensable part of the aero-engine rotor system,the bearing has a direct influence on the running state of the engine.The reliability of aero-engine bearing is evaluated through the history failure time data and the vibration signal of operation conditions,which combined with the reliability model respectively.In order to avoid accidents,the status of aero-engine in operation can be grasped more effectively.The traditional reliability analysis is based on the large sample data,but it is very difficult to obtain and will be far from the practicability.This paper puts forward the reliability analysis method of the aero-engine bearings’ fault time data and vibration measurement data,which in order to analysis the reliability of different data respectively.Based on the three-dimensional modeling of the bearing,the analysis of harmonic response under different loads is gained in ANSYS,and the dynamic stiffness function is obtained by combined with MATLAB.The specific researches have been carried out as follows:1)A Bayesian hierarchy model based on small sample is used to analyze the failure time data of aero-engine bearing and a distribution model is established.Through the analysis of the failure time data,which obtained the reliability of aero-engine bearing at different time and tested the model.2)The wavelet information entropy is selected to analysis the vibration signal of bearing.The normalized wavelet information entropy is obtained by denoising the vibration signal and calculating the frequency band energy.And the reliability of normalized wavelet information entropy under four kinds of different fault degree bearing can be obtained.3)Through modeling and analysis the studied bearing,the change of the shape under stress can be seen by modal analysis and the resonance frequency is obtained by the harmonic response analysis.The results of finite element analysis are combined with the dynamic stiffness formula,through the MATLAB program to fit the function relation of the dynamic stiffness.4)The GUI(Graphical User Interfaces)for the reliability analysis of aero-engine bearings is established on the basis of MATLAB.Especially for the analysis of vibration data,which can improve the readability,convenience and simplicity of the process of aero-engine bearing reliability analysis.