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论文类型：期刊论文

发表时间：2015-02-01

发表刊物：JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES

收录刊物：SCIE、Scopus

卷号：3

期号：1

页面范围：49-64

ISSN号：2321-3558

关键字：Continuum rotor; Bearings; Electromagnetic force; Bifurcation; Chaotic vibration

摘要：A new, continuum model based on the theory of Euler-Bernoulli beam is proposed for rotor-bearing system excited by transverse electromagnetic force. The nonlinear electromagnetic force is modeled as a steady-state loading. Two distinct analytical models of oil-film force of bearing are introduced with the Sommerfeld and the half-Sommerfeld boundary conditions, respectively. The governing partial differential equations of motion are discretized through the Galerkin's method and numerically solved using the Runge-Kutta method with adaptable step-sizes. The dynamics of the rotor-bearing system is illustrated through bifurcation diagrams, fast Fourier transformations and Poincar ' e maps. The numerical analysis indicates that the nonlinear motion response of the system is influenced by both the electromagnetic force and the oil-film force. With the increase of rotation speed, various kinds of periodic, multiperiodic, quasi-periodic and chaotic vibrations are observed in motion response of the rotor. The oil-film forces derived with the Sommerfeld and the half-Sommerfeld boundary conditions are separately used in numerical analysis, and the results are compared. The combined effect of the electromagnetic force and the oil-film force may lead to severe vibration and jeopardize the stability of the rotor. The presented continuum model of rotor can be used for similar systems excited by longitudinally distributed forces.