The Research On The Dynamic Model Of Rotor Systems With Nonlinear Fault And The Method Of Fault Diagnoisis

In this paper, the bifurcation and chaos motions of rotor system caused by nonlinear oil-film force,rub-impact force and other coupling nonlinear force have been studied. The dynamical responses with various fault have been solved. Analysis the rule of the system response with the variational parameters. On the basis of them.EMD method was used to decompose the rotor vibration signal into a number of intrinsic mode functions(IMFs).then,the sum of some IMF components which contain main fault information was computed to obtain the noise-reducing rotor vibration signals.Finally, the fractal dimension of the noise-reducing rotor vibration signal under proper embed dimension is computed.The main work is done as follows:1,The dynamic models of rotor-bearing system with foundation looseness,impact-rubbing and coupling of them have been founded. On the basis of that, analyze the movement of system on the effect of oil-film force, foundation looseness and nonlinear rubbing force.2,Get the response of rotor system dynamics equation by using the analysis methods of numerical value. the bifurcation diagrams, poincare maps, phase plane portraits , axis portraits and time-history curve of rotor motion were used. to analyze the .course of periodical response, quasi-periodical response ,double-periodical bifurcation, chaos of the system .3,According to the analysis of response diagrams, it attained some useful conclusions. For example,ways to chaos and different parameters have some concrete influences on rotor system response, which have offered theorical reference for real engineering.4,EMD and fractal dimension were used for analysis fault signal and find some characters of the fault signal,the method is proposed by computing the fractal dimension to identify the work state and fault pattern for the rotor system efficiently. The paper's innovation: based on the nonlinear dynamic behaviors of rotor-bearingsystem caused by nonlinear oil-film force and rub-impact force .the EMD and fractal dimension were applied to identify the fault pattern for the rotor-bearing system efficiently...