【摘要】 建立了带有裂纹故障的双跨弹性转子系统的动力学模型,利用求解非线性非自治系统周期解的延拓打靶法和Floquet理论,研究了系统周期运动的稳定性及失稳规律。系统以倍周期分岔形式失稳,且在不同转速下,系统会出现倍周期分岔和Hopf分岔等不同的分岔形式。在亚临界转速区系统响应中出现了1/3倍频、1/2倍频、2/3倍频、1倍频、2倍频等频率成分,但是在超临界转速区,2倍频及以上频率的峰值明显减小。更多还原

【Abstract】 A dynamic model was set up for a two-span and rotor-bearing system with crack fault.Using the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system,the stability of the system periodic motion was studied by the Floquet theory.The periodical,quasi-periodical and chaos motions were found in the system responses.The unstable form of the rotor system with crack fault is period-doubling bifurcation.There are unstable forms of period-doubling bifurcation and Hopf bifurcation in different rotate speed.There are many harmonic elements of 1/3,1/2,2/3,1,2 and so on within the sub-critical speed range.But the 2-harmonic element decreases within the super-critical speed range.The results from this work provide a fundamental basis for the failure diagnosis of the rotor-bearing system.更多还原