Stiffness And Damping Identification Of Flexible Rotor Bearing System

The rotor system supported by oil film bearing is widely used in aviation,aerospace,machinery and other fields because of its high performance.The support parameters are very important to the stability of the system.In this paper,a certain type of flexible rotor-oil film bearing is taken as the research object.Considering the influence of rotor bending deformation caused by high speed on the stiffness and damping of oil film bearing,the bearing parameters of oil film bearing system at different speeds are successfully identified.Based on the Kirchhoff plate theory,the structural finite element method is used to calculate the elastic modulus of the thin plate at each temperature by using the response displacement data at different temperatures obtained by simulation,and the elastic modulus is recorded as a nominal value.Using the response surface method,the response approximation function is fitted by the least square method.On the basis of the nominal value,the error response surface of the elastic modulus is constructed,and the identification error caused by the high temperature factor is solved.The identification of the elastic modulus is realized,and the effectiveness of the identification method is proved.A mechanical model of a rigid rotor-oil film bearing system is constructed.The stiffness and damping of the bearing at a certain speed are calculated by using multiple sets of displacement response data measured by repeated tests,and recorded as the nominal values of stiffness and damping.The response surface method is used to fit the response approximation function by using the least square method and the BP neural network method respectively.The error response surface of each support parameter is constructed to solve the identification error caused by the flexible deformation of the rotor,and the stiffness and damping of the flexible rotor-oil film bearing system are identified.the effectiveness of the identification method is verified by comparing the experimental data with the simulation data of a certain type of flexible rotor-oil film bearing test bench.The rotor support model,external excitation and system response are successfully linked.