Reliability Analysis Of Rotor System Based On Random Finite Element

The current states of Rotor dynamics and reliability is summarized in this thesis.Based on these aspects,the three plates rotor system with eccentric mass,bearing stiffness and damping is researched.The response equation of the system is established by the Finite Element Method.The trend of displacement of disk mass center along with time is researched.The Monte Carlo method for random sampling is used.The change curve about the mean value and standard deviation of the radial displacement of plate are gotten.Combined with sensitivity technology,the formula of response sensitivity of the system is established.The change curve of sensitivity about the random response relative to the random parameter is calculated.It is researched the influence of the statistical properties of random parameters on the radial displacement of the plate.The analysis result indicate that the important factors influencing radial displacement of the rotor system are the mass and eccentricity of the three plates.Therefore,these parameters should be strictly controlled in the actual production.The each order natural frequencies of the rotor system is gotten.According to the failure criterion that the absolute value of the difference between the natural frequency and the driving frequency of rotor systems is not beyond a specific value.The limit state equation of rotor system is defined.The reliability of rotor system under various failure modes is calculated.The Monte Carlo method for random sampling is used.The mean value and standard deviation of the natural frequencies of the rotor system is gotten.The reliability sensitivity of each parameter to the rotor system natural frequency is calculated.The influence of the statistical characteristics of random parameters to the natural frequency of rotor system is studied.The double plates rotor system as a research object is token.The response equation of the rotor system is established.The first natural frequency and the critical speed of the system is gotten.According to the relationship between the excitation frequency and the natural frequency of the rotor when the oil whip occurs,the limit state equation of the system is established.According to the failure criterion that the absolute value of the difference between the natural frequency and the driving frequency of rotor systems is not beyond a specific value.The limit state equation of rotor system is defined.Aiming at the failure modes of the two kinds of resonance problems,it is summarized that the method to estimate the reliability of the rotor system with oil whipping and resonance.The problem of reliability sensitivity of the rotor system with coupled failures is solved.The reliability sensitivity of the rotor system is analyzed systematically for the random parameters.