旋转轴弯扭振动测量的激光多普勒光学系统误差分析

在高速旋转机械的故障诊断研究中,实际转子系统具有复杂的非线性动力学特性,为此,基于非线性转子动力学理论建立高速泵转子系统动力学有限元模型,研究了非线性油膜力作用下的轴承阻尼和刚度确定方法,分析了陀螺力矩和滑动轴承油膜力作用等因素对转子系统动力学特性的影响,研究了转速、偏心距和轴段直径等因素对转子系统不平衡响应的影响,为工程实际应用中的转子轴承系统的优化设计、故障诊断、振动控制等提供了理论依据.     

不对称润滑对碰摩转子-轴承系统的动力学影响

在考虑非线性油膜力的基础上,建立了具有碰摩故障的转子-轴承系统的动力学模型。用数值方法研究了在非线性油膜力作用下具有碰摩故障的转子系统的动力学特性,并研究了当改变其中一个支承轴承润滑油的粘度时,转子系统的动力学特性。研究发现,随着一轴承润滑油粘度的降低,转子系统亚临界角速度区的混沌区域和拟周期区域扩大了。该结果为采用不同粘度润滑剂的转子-轴承系统的优化设计、安全运行和故障诊断等提供了一定的理论参考     

单跨双圆盘不平衡转子-轴承系统的非线性动力学分析

根据30万kW发电机组模型试验台第一跨高中压转子的实际结构,考虑基于短轴承假设的非线性油膜力模型,建立了单跨双圆盘转子动力学模型。用数值方法进行了质量不平衡及油膜失稳条件下的动力学特性分析,得到系统稳态响应和分岔结果。讨论了非线性油膜的刚度特点。这些结果与试验基本一致。对转子-轴承系统的动态设计与故障诊断提供参考。     

转子轴承系统油膜力特征的非线性动力学分析

建立了非线性油膜力作用下的转子-轴承系统的动力学模型,应用非线性动力学理论对该系统进行了研究,应用数值方法得到转子-轴承系统的油膜力大小随转子回转角速度Ω变化的曲线,得出油膜力的形状及刚度与转速密切相关;根据油膜力-位移曲线,显示出油膜力的强非线性.为有效诊断滑动轴承支撑下的转子-轴承系统油膜涡动故障提供了理论依据.     

不确定转子耦合系统的经验参数研究

提出用非线性动力学行为进行不确定转子-轴承-密封耦合系统经验参数的研究,结果旨在为选择重要经验参数和实际控制转子的稳定运行提供依据.基于Muszynska模型和Capone圆轴承非线性油膜力模型,推导建立密封流体激振力和油膜力共同作用下的参数不确定转子-密封-轴承系统非线性动力学方程,通过数值分析,研究了该系统在平均周向速比常数影响下的分岔特性以及影响规律,并分析了几个特定参数下系统随转速变化的分岔特性和非线性动力学行为.分析结果发现,平均周向速比常数对系统的非线性动力学行为影响很大,随着平均周向速比常数的增大,系统提前出现倍周期分叉,并且振幅增大,使得不稳定性增加.基于上述分析,给出了合理的平均周向速比常数取值范围.     

带有支座松动故障的离心泵叶轮转子分岔特性分析

将离心泵叶轮转子系统简化为中间带有刚性圆盘的柔性转子,在引入非线性横向流体激振力的条件下,建立带有支座松动故障的不平衡离心叶轮转子在非线性轴承油膜力作用下的振动模型,并推导系统的无量纲运动方程.运用数值积分法研究系统的分岔特性,分析横向流体激振力以及松动端轴承支座质量对该类离心泵叶轮转子系统非线性动力学特性的影响.     

松动-裂纹耦合故障转子系统的非线性动力学行为研究

以现代非线性动力学和转子动力学理论为基础。分析了带有一端轴承支座松动和裂纹耦合故障的弹性转子系统的复杂非线性现象。针对非线性转子一轴承系统的具体特点，采用短轴承油膜力模型。应用Runge—Kutta法数值模拟得到的系统在某些参数域中的分岔图、Poincare映射和频谱图等反映了系统的运动状态，并分析了该耦合转子系统的故障特征，研究结果对该类转子-轴承系统的故障诊断和预防提供一定的参考。     

对挤压油膜阻尼器轴承和旋转机械转子—挤压油膜阻尼器轴承系统动力特性研究的回顾与展望

简要介绍挤压油膜阻尼器轴承及其基本分类，介绍各种挤压油膜阻尼器轴承的动力学特性研究和建立阻尼器流体动力模型与挤压油膜力的进展情况，总结了支承在挤压油膜阻尼器轴承上的旋转机械转子系统的动态响应特性和稳定性的研究结果及对这类强非线性的转子－阻尼器支承系统的非线性响应特性研究的进展情况，并对该类减振结构的未来发展进行了展望。     

转子-轴承-密封耦合系统的非线性振动特性研究

结合短轴承非线性油膜力模型和Muszynska密封力模型,运用数值积分方法分析了转子-轴承-密封耦合系统的非线性动力学特性,针对转速对耦合系统动态响应的影响进行了仿真计算,并利用转子中心分岔图、轨迹图、Poincare映射图、功率谱图分析了耦合系统的非线性动力学特性.理论分析表明:随着转速的变化,耦合系统呈现复杂的动力学行为,产生了包括单周期、3倍周期、拟周期等振动现象.     

非线性弹性碰摩转子周期运动稳定性分析

在同时考虑轴承油膜力、转轴非线性弹性力和碰摩发生时转静件间的相对速度对非线性摩擦力的影响基础上,构造了具有碰摩故障转子-轴承系统的动力学模型。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,分析了非线性摩擦力对系统动力学特性的影响。     

高速转子-轴承系统油膜涡动故障仿真研究

针对滑动轴承支撑下的转子轴承系统,建立了非线性油膜力作用下的转子轴承系统的动力学模型.应用非线性动力学理论对该系统进行了研究,应用数值积分方法得到系统的响应,利用幅频曲线、分岔图、三维谱图研究系统响应随偏心距的变化规律.为有效诊断滑动轴承支撑下的转子油膜涡动故障提供了理论依据.     

Dynamic characteristics of multi-degrees of freedom system rotor-bearing system with coupling faults of rub-impact and crack

Extensive studies on rotor systems with single or coupled multiple faults have been carried out. However these studies are limited to single-span rotor systems. A finite element model for a complex rotor-bearing system with coupled faults is presented. The dynamic responses of the rotor-bearing system are obtained by using the rotor dynamics theory and the modern nonlinear dynamics theory in connection with the continuation-shooting algorithm（commonly used for obtaining a periodic solution for a nonlinear system） for a range of rub-impact clearances and crack depths. The stability and Hopf instability of the periodic motion of the rotor-bearing system with coupled faults are analyzed by using the procedure described. The results indicate that the finite element method is an effective way for determining the dynamic responses of such complex rotor-bearing systems. Further for a rotor system with rub-impact and crack faults, the influences of the clearances are significantly different for different rub-impact stiffness. On the contrary, the influence of crack depths is rather small. The instability speeds of the rotor-bearing system increase due to the presence of the crack fault. The results obtained using the new finite element model, presented for computation and analysis of dynamic responses of the rotor-bearing systems with coupled faults, are in accordance with measurements in experiment. The formulations given can be used for diagnosis of faults, vibration control, and safe and stable operations of real rotor-bearing systems.     

Influence of the Mechanical Seals on the Dynamic Performance of Rotor-Bearing Systems

In this paper, to consider the effects of mechanical seals, a lumped-mass model and the transfer matrix method are used to establish the equations for the dynamics performance of rotor-bearing system. The general inverted iteration method is also used to solve the eigenvalue problem of these equations. To check the response of the rotor-bearing system under unbalance motivation, the Gauss method is used to calculate the dynamic response of the constrained vibration. The results, based on the dynamic properties calculation of a typical mechanical spiral seal, such as stiffness coefficients and damping coefficients, exert the influence of the mechanical seal on the rotor-bearing system of the high-speed machinery. Meanwhile, some structure parameters that may affect the dynamic performance and forced vibration under unbalance motivation of the rotor-bearing system considering mechanical seals are analyzed in the paper. The analysis results show that the mechanical seal more or less has effects on the rotor-bearing system. The mechanical seal has much more effects on the flexible rotor-bearing system than on the rigid one. For instance, in a certain case, if the effects of the mechanical seal were taken into account, the systems critical speed may increase by 70–80%. Translated from Journal of Xi’an Jiaotong University, 2004, 38(7)     

摇摆工况下错位瓦轴承支撑的转子系统动力学特性

基于轴承刚度和阻尼的分段线性化假设,建立了不同横摇角度的转子轴承模型;利用DLAP软件,耦合求解错位瓦轴承支撑的转子系统的动力学模型;采用特征值和特征向量、不平衡响应分析、稳定性分析和瞬态动力学分析等手段,研究了轴系的稳定性和安全性,并与正常工况下轴系的动力学特性对比,得到了摇摆工况下错位瓦轴承支撑的转子系统的动力学特性。     

双跨碰摩转子-轴承系统非线性动态响应与混沌

在同时考虑轴承油膜力和碰摩发生时转静件间的相对速度对非线性摩擦力的影响基础上,构造了双跨碰摩弹性转子-轴承系统动力学模型。对系统单盘和双盘碰摩的非线性动力学响应进行了数值仿真研究,发现该类系统在单盘碰摩时进入混沌的道路是倍周期分岔,离开混沌的道路为倍周期倒分岔,混沌运动区域为一体;双盘同时碰摩时,混沌运动区域中出现了2个明显的独立混沌岛。偏心量的增大,会使得系统响应更加不稳定。研究结果为转子-轴承系统故障诊断、动态设计和安全运行提供了理论参考。     

Dynamics analysis of a cracked dual-disk over-hung rotor-bearing system

A dynamic model of a dual-disk vertical over-hung rotor-bearing system is developed, taking into account nonlinear oil-film force. Its dynamic behaviors are investigated by numerical Runge-Kutta method. Its bifurcation and chaos characteristics are analyzed with crack fault and without crack fault. By analyzing the bifurcation plot, Poincare section plots and amplitude spectra, we found that the crack greatly influences the dynamic characteristics of the rotor-bearing system. Because of the strong effect of the nonlinear oil-film force and crack to the system, 1/2 times, 1/3 times frequency components appear in the response spectrum map. The results may bring up theoretical references for fault diagnosis of rotor-bearing systems. __________ Translated from Journal of Vibration Engineering, 2005, 18(1) (in Chinese)     

Stability of periodic motion on the rotor-bearing system with coupling faults of crack and rub-impact

A dynamic model was set up for the 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 was studied by the Floquet theory. The saddle-node bifurcation, periodic-doubling bifurcation and the Hopf bifurcation were found. There are peculiar dynamic characteristics of the rotor-bearing system with coupling faults of crack and rub-impact that differs from single fault. The conclusions provide theoretic basis reference for the failure diagnosis of the rotor-bearing system with coupling faults of crack and rub-impact fault.