建立带有裂纹—碰摩耦合故障的具有三轴承支承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,研究系统周期运动的稳定性及失稳规律。双跨裂纹转子系统以倍周期分岔形式失稳,双跨碰摩转子系统以Hopf分岔形式失稳,当裂纹较小时,裂纹—碰摩耦合故障转子—轴承系统以Hopf分岔形式失稳;随着裂纹深度的加大,其影响逐渐显现,系统以倍周期分岔形式失稳,且失稳转速降低;耦合故障转子系统响应谱上存在半倍工频成分的整数倍频率成分。研究结果为转子—轴承系统耦合故障诊断和安全运行提供了参考。
A dynamic model is set up for the two-span rotor-bearing system with coupling faults of crack and rub-impact.Using the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system,the stability of the system periodic motion is studied by the Floquet theory.The unstable form of the rotor system with crack fault is period-doubling bifurcation,and that with rub-impact fault is Hopf bifurcation.The unstable form of the rotor system with coupling faults is Hopf bifurcation when the depth of crack is smaller.The influence to the response of the system increased along with the depth of crack,the unstable form of the rotor system with coupling faults is period-doubling bifurcation.The conclusions provide theoretic basis reference for the failure diagnosis of the rotor-bearing system.