【摘要】 从一个由三个函数确定的非稳态油膜力的非线性模型出发 ,以短轴承支撑的刚性Jeffcott转子系统作为研究对象 ,采用短轴承油膜力的解析表达式和数值模拟的方法研究了系统的分岔和混沌特性 ,并将模拟结果与稳态油膜力模型的模拟结果作了比较 ,证明了该非线性模型的合理性。更多还原

【Abstract】 The stability of a rigid Jeffcott rotor supported by short journal bearings is discussed,focusing particular attention on its nonlinear aspects.A more reasonable nonlinear unsteady oil film force model,which is determined only by three functions,is adopted in the paper and the explicit analytical formula of oil film force for short journal bearing is used for bifurcation and chaos study.The bifurcation diagrams of an assigned rotor with fixed values of the dimensionless mass eccentricity ρ are investigated when its angular speed is varied.Poincare maps of the phase portraits the rotor system are used in the paper to explore the motion of journal center.The dimensionless mass eccentricity ρ influences the motion of the journal,especially when the dimensionless mass eccentricity ρ =0.3,the motion becomes very complex,synchronous whirl,periodic doubling,quasi periodic and chaos occur alternately.The results have been compared with the results under steady model,the threshold value of angular speed at which the system will lose stability is much higher than that of steady model,it is much accordant with engineering fact.The present analysis has shown that the model adopted in the paper is more suitable for rotordynamic applications.更多还原