Nonlinear Estimation And Parameter Optimization Method For Dynamic Behavior Of Sliding Bearing-rotor System

As a crucial component of rotating machinery,rotor-bearing system is widely applied in aerospace,shipbuilding,power and other industries.With increasing development of economy and progress of science and technology,rotating machinery is developing in the direction of high speed,light weight,high flexibility and large load,due to which production efficiency is improved and production cost costs are reduced.However,it is accompanied by nonlinear problems that cannot be explained by traditional linear theory,which leads to a number of major safety accidents.In this context,in this paper,sliding rotor-bearing system was selected as research object,system nonlinear measure method was used to conduct quantitative research on nonlinear dynamics of rotor-bearing system,which was used as objective function to optimize system structure parameters.The research results can provide certain theoretical references for the design of rotor system parameters.The main research work of this paper is as follows:1.By considering nonlinear oil-film force and nonlinear elastic force,a dynamic model of sliding rotor-bearing system is established.The established dynamic model of rotor system is experimentally verified through the construction of a vibration test stand of rotor system.Runge-Kutta method is used to carry out simulating calculation of the model.Effects of rotor speed,eccentricity,lubricating oil viscosity and bearing clearance on the dynamic behavior are analyzed from different angles,and influence mechanism of structural parameters of rotor system on its dynamic characteristics is investigated in depth.2.System nonlinear measure theory is used to conduct quantitative research on the complexity of nonlinear dynamic behavior of rotor system to address the limitations of traditional nonlinear problem analysis methods.A linear approximate dynamic model is obtained through nonlinear taylor expansion of the nonlinear model.System nonlinear measure values under different parameters are calculated through nonlinear measure definition.Quantitative analysis is carried out to study the influence mechanism of rotor speed,eccentricity,lubricating oil viscosity and bearing clearance on nonlinear dynamics of rotor system.3.For the established rotor system dynamic model,optimum structural design based on improved particle swarm optimization is introduced to optimize bearing parameters of sliding rotor-bearing system by taking rotor system nonlinear measure values as objective function.By comparing results of particle swarm optimization with that of exhaustion method,it is concluded that the former has advantages of fast convergence and strong global search performance.Simulation analysis of optimization results is conducted,and the results show that the rotor system with optimized parameters has strong periodic response and simple dynamic behavior,which verifies the effectiveness of the method.