Experimental Study On Effect Of Random Support Stiffness Parameter On Dynamic Characteritics Of Rotor System

Support stiffness parameter is an important dynamic parameter of the rotor system, and ithas an important effect on dynamic characteristics of the system. In actual engineering, itsstiffness model often stochastic due to manufacture、installation、operation、maintenance andother kinds of factors, so it can reflect the actual situation that the stiffness model describingwith the random parameters model. The theoretical results of that research on the randomsupport stiffness parameter affecting dynamic performance of the rotor system are many.However, experimental study on random support stiffness dynamic problems need to a largenumber of test pieces, which in research time and cost are not allowed. Therefore, theinterrelated research results are very little. A low-cost random support stiffness parametersimulated test platform is designed and processed, experimental study on effect of randomsupport stiffness parameter on dynamic characteristics of totor system in this paper. The mainresearch contents and results in this paper include the following aspects:1. A kind of vibration signal analysis and measurement system was designed anddeveloped, which is based on virtual instrument technology. The system is designed onLabVIEW workbench, and it can measure the vibration signals of rotor system.2. Based on the working principle of electromagnetic support, electromagnetic supportwas designed and processed with the existing rotor test-bed as the research object, and appliedthe electromagnetic support to the test-bed, electromagnetic support-rotor-bearing system wasconstructed. It can simulate the random support stiffness parameter of rotor system inlaboratory. Took electromagnetic support-rotor-bearing system as the research object, variousindefinite parametes affecting dynamic performance of totor system was analyzed when theelectromagnetic support without excitation current. One kind of experimental technique wasgiven by identification of these indefinite parameters gradually, and identified these indefiniteparameters. The experimental research model of electromagnetic support-rotor-bearingsystem was established, and eliminated the disturbance factors for the experimental study onrandom support stiffness rotor system natural frequency.3. Took electromagnetic support-rotor-bearing system as the research object, the rotorsystem natural frequency with0~200mA excitation current were tested. The support stiffnessof the electromagnetic support with different excitation current were identified and the linearwork area of electromagnetic support was searched. When the electromagnetic support worked in linear work area, there was a linear relationship between rotor system supportstiffness and the exciting current, so the system support stiffness parameter can be randomlycontrolled by the controllable random electric current.4. Took electromagnetic support-rotor-bearing system as the test platform, a kind ofexperimental technique which can realize the varying of the rotor system support stiffness wasgiven. When random stiffness parameters accord with normal distribution, the mean, varianceand random distribution of rotor system natural frequency were studied through theexperimental means. It shows that this method can realize the varying of rotor system supportstiffness and the experimental results are credible by comparing the actual value withperturbation value and analogue result by Monte Carlo. It reduces the experiment cost,enhances the economic efficiency. The experimental platform can be used to study onfollow-up random dynamic response problems of rotor system.