The Reliability And Sensitivity Study Of Oil Whirl And Whip-rotor/bearing With Stability Problem

With the development of science and the advancement of society, rotary machine become widely used in many fields such as Aviation, Transportation, Energy and so on. And the society requires higher performance to rotating machines. The rotating machines are becoming higher speed, heavier load and automation. Because of many kinds of complicated facts, the rotating machines often have many different kinds of faults. This not only influents their normal performances, but also results in serious accidents which cause the operators'deaths and loss of wealth. So it has great meaning to study the dynamics behaviors of the rotating machines.In practical cases , the rotor-bearing systems are uncertain. These uncertainty is resulted form the uncertainty of the engineering material property and the dimension. And these systems are always working under uncertain loads. So the traditional designing which take the parameters as certain ones is not practical. The designing method which based on the probability and statistics theory should be advocated in order to make the design more practical and meet the engineering's need.This paper uses the model of uncertain rotor-bearing system and do a failure investigation of unsteadiness of oil film in a rotating machine. First of all, analyze the stochastic response of a uncertain rotor-bearing system with nonlinear oil film forces using the probability perturbation finite element method and shooting method. Then, analyze the sensitivity of the response f depend of six stochastic parameters [c, k11, k12,μ, L, R]. Third study the reliability and reliability sensitivity of the system using the statistical four moment method and Edgeworth series technique and give the numerical answer. It is more practical to engineering using the Edgeworth series technique because it can approximately simulate the unknown distribution function of the state function of the system.