Research On Dynamic Behaviors And Controls Of Rotor System With Rubbing And Oil Film Coupling Fault

The rotor system is not only an important part of rotating machinery, but also a keycomponents of some mechanical equipments such as rotor pump etc. Rubbing of rotor systemis one of the common faults in rotating machinery, because as one of the main nonlinear fault,it has very strong nonlinear characteristics of vibration. Rubbing of rotor system directlyaffects the normal operation of this kind of mechanical equipment, therefore to carry out theanalysis of dynamic characteristic for this type of structure optimization design about rubbingrotor system and stable operation of the machinery have important significance. The mainwork in this paper including:1Introduced the background of chaos, The present situation of the rubbing rotor systemis also analyzed, the purpose, meaning and some problem in this area are specified. At thesame time, This paper introduces the definition and general characteristics of chaos, alsoclarify the control theory about Chaos and how to judge chaos.2The dimensionless motion differential equations under rigid Jeffcott rotor rubbingforce balance has been set up. Based on the rubbing Jeffcott rotor dynamics model, equivalentdimensionless equation is obtained through transformation, Do analysis of stability about thebalance of equation. Hwertize determinant is used to judge the system equations, in this waywe can know the value of speed ratio when the Hopf bifurcation occur. We furthervalidation that use the simulation, We concluded that theoretical analysis and numericalsimulation are consistent.3The Jeffcott piecewise smooth model is studied, rubbing force in nonlinear systemmodel isgiven and the differential equations of dimensionless, after get the dimensionlessequation for equilibrium analysis, are given with different sets of parameters to calculate thecharacteristic value to judgment of the stability, through a series of parameter analysis of thestability is calculated through the formula deduction, and the two table arrangement, whichcan control system stability of equilibrium point under some parameters. Then according tothe Hurwitz determinant criterion system in speed than Hofp bifurcation occurs when areawhat value, to determine Hofp bifurcation points in speed than and values, is obtained bynumerical simulation in speed than the bifurcation diagram, phase diagram, poincare map,you can see the Hofp bifurcation point and calculated by numerical simulation are consistent,and these graphics more intuitive to reflect the dynamic behavior of the system.4Dynamic model is established about the rotor-bearing system, When do these, thecoupling about nonlinear oil film force and nonlinear rubbing force on bearing is takenintoconsideration. We do numerical simulation about dynamic characteristics of rotor rubbing,In the process, Standard of fourth order Runge-Kutta method is be used. At the same time, analysis the nonlinear response after rubbing occurs of the system, in the process of analysiswe use some tools such as lyapunov index figure, waveform graph, axis locus figure, thephase diagram, spectra figure and the poincare map etc. By adjusting the parameter of thedynamic behavior of the research can get the optimal control rangethe of the system under thedifferent parameters. After this we control the chaotic behavior of system at speed ratio，themethod we use is named washout-filter state feedback control method. This chapter mainlyanalyzes the dynamics behavior of the rubbing rotor oil film force, first analysis with speedthan changes in the system dynamics behavior changes, with the increase of rotational speedthan system presents a cycle, bifurcation, quasi-periodic and chaotic complex dynamicbehavior, draw a system the optimal control working range. And through the comparison ofdifferent oil film force of the bifurcation diagram and the Lyapunov index figure, still can tellwhich oil film force of the running state of the system is best, Changes to the aboveparameters under the bifurcation diagram, axis path waveform diagram, phase diagram, figure,poincare section analysis can be seen after add oil film force of rubbing rotor system, Systemdynamics become more complex, more time to present a state of chaos. Finally application ofwashout filter-feedback control method to the introduction of state feedback controlvariables in the system, After researcher show that this kind of method can effectivelysuppress chaos phenomena occurred in the system...