Power Flow Transmission Characteristics Research Of Complex Coupled Vibration System Based On The Finite Element Analysis

Along with the development of modern technology, the power of the mechanical equipment is continuously increased, and then vibration source energy constantly strengthened. So problems of human production and life caused by mechanical equipment vibrations are becoming more and more outstanding. Therefore, technology of vibration control is of strong practical value.In the theory of power flow the vibration transmission characteristics of system are analyzed from the aspect of energy. Because power flow contains two parameters, the force and the speed, it can give vibration an absolute measure and reflect the vibration information more comprehensively. Therefore, the theory of power flow not only can be used to study the vibration transmission characteristics between each subsystem, also can be used to confirm vibration reduction of the vibration control strategy by considering the power flow value that comes into the aim system as an evaluation standard.In this paper, the power flow transmission characteristics of complex coupled system was researched based on the method of the finite element analysis. The power flow of coupled vibration system was calculated through an actual example and its transmission performance was studied. The model that can be used to research the power flow transmission of complex coupled vibration system was established using large general finite element software by combination of vibration power flow theory and the finite element dynamics analysis.Bearing is the supporting structure commonly used in rotating machinery, and as the vibration transmission path in a complex coupled system, the flexible and six degrees of freedom on the coupled effects must be fully considered in the system modeling. In this paper, the power flow admittance model of bearing was introduced to the structure modeling of the finite element software, and the finite element model of bearing coupling structure was set up. The validity and accuracy of the finite element model was verified through the experimental modal analysis of vibration test bench. Then the finite element bearing model was applied to the power flow transmission analysis of vibration test bench system, which lay the foundation for power flow transmission analysis of complex coupled vibration system.Based on the finite element bearing model, the finite element model of complex coupled vibration system was built using a gearbox as the research object. The gear box and the whole system including gear and shaft were studied by the finite element modal analysis. Research shows that the modal frequency of vibration under these two kinds of models is very obvious difference, and the finite element modal analysis might use the whole system model in engineering application.Then the vibration power flow transmission of the finite element gearbox model was analyzed in this paper. By giving an outside incentive, distribution of the vibration power flow that input to the subsystems of the gearbox in frequency domain was obtained. To the vibration power flow transferring to the gear box plate, the contribution of different degrees of freedom was analyzed. Based on this finite element gearbox model, the influence to vibration power flow transmission characteristics of bearing damping, bearing stiffness, box material, gear material and shaft material in the gearbox system was studied.The finite element model of complex coupled system built by using the gearbox system as the research object in this paper provides effective way of studying for considering system vibration condition in the design phase when rotating machinery equipment is running, and supplies computer aided design basis for evaluation of such equipment vibration performance.