| Support stiffness parameters are important dynamic parameter of the rotor system, andhave an important effect on dynamic response of the system. In the actual rotor system,because of such problems as the friction of the axis of rotation and the disc surface, thematerial resistance of shaft, design size, and operation mode, stiffness model of the system isoften with stochastic characteristics.So it has become an important research topic to study theeffect of random changes of support stiffness parameters on rotor system unbalanced response.Although scholars have done such a large amount of research, but their researches mostlyconfine to the theoretical study. In this paper, in the case of knowing the external unbalancedforces, combined with the already designed, processed physical experimental platform whichcan simulate random support stiffness parameters, the influence of random support stiffnessparameters on rotor system dynamics response is studied with the utilization of experimentalmeans. The thesis mainly does the following aspects of work:1. To take rotor-bearing system as the research object, according to the spot dynamicbalance experiment principle, the critical speed of the rotor system was tested. Combined withexperience value, the rotor system spot dynamic balance and the rotating speed of the lateresponse experiments were confirmed. Using the dynamic balance meter SB-8002to do thedynamic balance for rotor-bearing system and to make the residual balancing of therotor-bearing system to a minimum, and then the residual balancing under balanced isevaluated.2. To take electromagnetic support-rotor-bearing system as experimental study platform,using steady dc sources and power amplifier to ventilate the electromagnetic support with thesame exciter current respectively, measured the displacement response of the electromagneticsupport on the condition of no electricity and electricity, using dynamic analysis softwareRotors Dynamics,analyzed imbalance response of the rotor system,to take the total error ofthe experimental value and analysis data of the displacement response maintained within20%as the principle, amount of imbalance of the rotor system and the support stiffness parametersof small and big sliding bearing were identified out.3. To take linear relationship of certain electromagnetic support stiffness and randomcurrent as the foundation, in the condition of rotating shaft, the displacement response wasmeasured when the rotor system rotates and electromagnetic support was ventilated with 100-180mA current, The relationship between the current and support stiffness and therelationship between the support stiffness and the displacement response were bothconcluded.4. To take electromagnetic support-rotor-bearing system as the research object, ventilatedthe electromagnetic support with random current whose mean value was140mA and thevariation coefficients were0.1,0.15, the displacement response of the rotor system wasmeasured, and the mean value and variance of the displacement were obtained. By comparingthe experimental value with Monte Carlo simulation value and perturbation value, the effectwhich was the digital characteristics of random support stiffness rigidity parameters upon thedisplacement response digital characteristics of the rotor system was analyzed, and thecorrectness of the theory was verified. |
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