多故障转子系统的非线性动力学分析与实验研究

发布时间：2019-04-02 19:53

【摘要】：转子系统作为旋转机械的核心部件,研究其故障状态下的非线性行为和动力学特性对理解、控制转子系统的故障有深远意义。本文从理论仿真上研究了裂纹、碰摩、油膜失稳单故障以及多种故障同时存在的情况,在考虑裂纹时变刚度、碰摩力、非线性油膜力的基础上,建立了刚性支承和油膜支承的转子动力学模型,采用龙格库塔法(Runge-Kutta)求解系统的动力学响应,讨论参数变化对系统非线性行为和动力学特性的影响,并分析了裂纹、碰摩、油膜失稳之间的相互作用。在实验研究方面,进行了刚性支承和油膜支承下的多故障转子系统实验,与理论仿真结果有较好的对应。通过理论和实验研究,得到了一些有价值的结论,为转子系统设计和工程实践应用提供了重要参考。主要研究内容包括:1.以刚性支承的Jeffcott转子为研究对象,建立了裂纹故障、碰摩故障以及裂纹-碰摩双故障的转子系统模型,采用Runge-Kutta方法进行求解,讨论了裂纹深度、动静刚度比、不平衡对系统动力学响应的影响;2.以油膜支承的双圆盘转子为研究对象,在考虑裂纹时变刚度和非线性油膜力的基础上,建立了转子系统的动力学模型,使用Runge-Kutta法求解,结合分岔图、频谱图、Poincaré截面图和三维谱图等分析了系统的分岔行为和动力学响应,得到裂纹和油膜失稳之间的作用规律;3.以油膜支承的多故障转子系统为研究对象,基于裂纹时变刚度、碰摩力、非线性油膜力,建立油膜支承下含裂纹-碰摩故障的转子模型,通过数值方法求解系统响应,借助分岔图、最大Lyapunov指数(LLE)、频谱图、Poincaré截面图等,讨论了转速、裂纹深度、定子刚度变化对系统响应的影响,获得了裂纹、碰摩、油膜失稳之间的作用规律;4.在Bently转子模拟实验台上进行了转子-轴承系统的故障实验研究。实验主要包括:刚性支承的正常转子和裂纹转子在加入碰摩故障前后的实验研究,油膜支承的正常转子和裂纹转子在加入碰摩故障前后的实验研究。获得了各故障形式下的系统响应,验证了相同模型下的理论仿真结果,对于转子系统的故障研究具有重要意义。
[Abstract]:As the core component of rotating machinery, the research on nonlinear behavior and dynamic characteristics of rotor system under fault condition is of great significance for understanding and controlling the fault of rotor system. In this paper, the problems of crack, rubbing, oil film instability single fault and multiple faults are studied in theoretical simulation. On the basis of considering the time-varying stiffness, impact force and nonlinear oil film force of crack, this paper studies the problem of crack time-varying stiffness, impact friction force, nonlinear oil film force, and so on. The rotor dynamics models of rigid support and oil film support are established. The dynamic response of the system is solved by means of the Runge Kutta method (Runge-Kutta). The influence of parameter variation on the nonlinear behavior and dynamic characteristics of the system is discussed, and the cracks are analyzed. The interaction between rubbing and oil film instability. In the aspect of experimental research, the experiments of multi-fault rotor system with rigid support and oil film support are carried out, which are in good agreement with the theoretical simulation results. Through theoretical and experimental research, some valuable conclusions are obtained, which provide an important reference for the design and engineering application of rotor system. The main research contents include: 1. Taking the Jeffcott rotor with rigid support as the research object, the rotor system models of crack fault, rub impact fault and crack-friction double fault are established. The crack depth, dynamic-dynamic stiffness ratio are discussed by Runge-Kutta method, and the dynamic-dynamic stiffness ratio of crack depth is discussed, and the dynamic-dynamic stiffness ratio of crack depth is discussed. The influence of imbalance on the dynamic response of the system; 2. On the basis of considering the time-varying stiffness of crack and the nonlinear oil film force, the dynamic model of rotor system is established, which is solved by Runge-Kutta method, and combined with bifurcation diagram and spectrum diagram, the rotor with oil film support is taken as the research object, and the time-varying stiffness of crack and the nonlinear oil film force are taken into account. The bifurcation behavior and dynamic response of the system are analyzed by Poincar茅 section diagram and three-dimensional spectrum, and the law of action between crack and oil film instability is obtained. 3. Taking the multi-fault rotor system with oil film support as the research object, based on the time-varying stiffness of crack, impact force and nonlinear oil film force, the rotor model with crack-impact fault under oil film support is established, and the response of the system is solved by numerical method. With the help of bifurcation diagram, maximum Lyapunov exponent (LLE), spectrum map and Poincare section diagram, the effects of speed, crack depth and stator stiffness on the response of the system are discussed, and the action rules among crack, rubbing and oil film instability are obtained. 4. The fault test of rotor-bearing system is carried out on the Bently rotor simulator. The experiments mainly include the experimental study of the normal rotor with rigid support and the cracked rotor before and after adding rub-impact fault, and the experimental study of the normal rotor with oil-film support and the cracked rotor before and after adding rub-impact fault. The response of the system under various fault forms is obtained, and the theoretical simulation results under the same model are verified. It is of great significance for the fault study of rotor system.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133

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