Research On Dynamic Characteristics Of Complicated Rotating System Based On Complex Coordinate

With the development of modern aviation, marine and other industries, therotating system is becoming more and more complex, owning to the interaction ofdifferent components and the exciting forces form inner and outer sources. Formulti-rotating system, the traditional computational analysis method is not yetmature. Also, for the rotating system containing planetary gear, the traditionallumped parameter model and finite element method are not yet valid. In view of this,the dynamic model based on complex space and transient dynamic model ofmulti-rotating system are established, meanwhile, the dynamic characteristic andtransit response of the system are probed. Finally, the dynamic model of planetarygear system is established, and the dynamic characteristics are analyzed.Based on the finite element method, the dynamic models of the cross-coupledrotating system and elastic disc in complex space are established. For the disc-rotorsystem, the impact of the thickness on the dynamic characteristics is analyzed. Theresults show that the system contains disc-rotor coupled mode, meanwhile, thedecrease of the thickness enhance the flexibility of the disc. In view of this, thecomputational analysis method of symmetric and asymmetric structure is derived.The Guyan reduction method is proposed due to the huge degree of freedom ofpractical model. The effects of different master-valve selection principle and numberof master degree of freedom on the dynamic characteristics of system are probed,guiding the selection of master degree of freedom in engineering. Studies show t hatGuyan reduction method can significantly improve the efficiency of modelcomputation. Keeping supporting nodes, floating ring and sealing related nodes,additional parameter nodes, connection related nodes, engineering concerned nodesand output nodes as master degree of freedom, which can significantly improve thecomputational efficiency, taken into account the accuracy.On the results of Jeffcott rotor transient dynamic analysis, the model andanalysis method of multi-degree-of-freedom rotor are proposed, and the transientanalysis of a turbo-generator unit is done under different angular acceleration. Theresults show that, with the increase of angular acceleration, the difference oftransient response and steady-state response increase. When the angular accelerationis large, the system present fluctuation phenomenon, whereas the trend is the samewith the steady-state one.Finally, the dynamic model is proposed for the planetary gear system, and thecomputational analysis method of dynamic characteristics is derived. The analysisresults of planetary gear system prove the validity of dynamic model and analysis method.