扭矩激励下多轮盘转子系统动力学特性研究

发布时间：2018-03-26 21:31

本文选题：多轮盘转子系统　切入点：扭矩激励　出处：《太原理工大学》2013年博士论文

【摘要】：多轮盘转子系统的结构比较复杂,在运行过程中,可能由于外加扭矩激励、初始轴弯曲等因素的影响,导致整个转子系统出现故障。目前,多位学者已开展了相关研究。然而,这些研究还有待深入。本文在此基础上,做了以下几方面的研究： (1)在传统扭矩激励表达式的基础上,对其进行了改进。分别对扭矩激励表达式改进前后仿真和试验结果进行了对比分析,结果表明：改进后扭矩激励表达式能更准确的反应实际转子系统扭矩激励的加载。 (2)在改进扭矩激励表达的基础上,考虑了非线性油膜力和弹性支承对多跨多轮盘转子系统的影响,建立了基于扭矩激励的多跨多轮盘转子系统模型及动力学方程,通过仿真和试验的方法分别研究了不同性质(线性、暂态)扭矩激励对多跨多轮盘转子系统各跨转子弯振的影响。结果表明：在不同性质扭矩激励(线性、暂态)的作用下,多跨多轮盘转子系统各跨转子振动幅值均未出现变化,而振动平衡位置出现向下偏移现象,并且各跨转子X向偏移量要明显小于Y向。 (3)在改进扭矩激励表达的基础上,考虑了弹性联轴器对多跨多轮盘转子系统的影响,建立了多跨多轮盘转子系统扭矩激励传递模型,推导了轴承负荷对扭矩激励的敏感度矩阵。通过仿真和试验的方法分别研究了多跨多轮盘转子系统不同性质(线性、暂态)扭矩激励的传递特性。结果表明：多跨多轮盘转子系统不同性质(线性、暂态)扭矩激励在X向和Y向的传递特性均不同,在同一扭矩激励作用下,多轮盘转子系统各支承X向和Y向轴承负荷对扭矩激励的敏感性响应不同。 (4)考虑了初始轴弯曲故障对多轮盘转子系统的影响,建立了具有初始轴弯曲的多轮盘转子系统模型及动力学方程,仿真分析了初始弯曲量、偏心距及阻尼比对多轮盘转子系统弯振的影响。通过小波和非线性流行方法实现了初始轴弯曲故障试验信号的特征提取及信号辨识。将仿真分析结果与提取的初始轴弯曲故障信号进行对比分析,并提出了具有初始轴弯曲的转子系统试验修正方程。 (5)在小波降噪和数学形态学降噪的基础上,提出了小波形态滤波法。分别采用形态学降噪和小波形态滤波法对仿真信号和轴承负荷试验信号进行了降噪处理,降噪结果很好地验证了小波形态滤波法对轴承负荷信号降噪的有效性。通过本文的研究,可以更为清晰地明白扭矩激励对多跨多轮盘转子系统的影响,更为清楚地认识到扭矩激励传递、初始轴弯曲故障信号以及轴承负荷信号的特点,为抑制扭矩激励干扰、转子系统典型故障诊断、提高转子系统试验信号采集效率奠定了坚实的基础。
[Abstract]:The structure of multi-disk rotor system is complex. During operation, the whole rotor system may fail due to external torque excitation, initial shaft bending and other factors. At present, many scholars have carried out related research. On the basis of this, this paper has done the following research:. 1) on the basis of the traditional expression of torque excitation, the simulation and test results before and after the improvement of the expression of torque excitation are compared and analyzed. The results show that the improved expression of torque excitation can more accurately reflect the loading of actual rotor system torque excitation. On the basis of improving the expression of torque excitation, the influence of nonlinear oil film force and elastic support on multi-span and multi-disc rotor system is considered, and the model and dynamic equation of multi-span multi-disc rotor system based on torque excitation are established. The effects of different characteristics (linear, transient) torque excitation on the bending vibration of multi-span multi-disk rotor system are studied by simulation and experimental methods. The results show that under different characteristics of torque excitation (linear, transient), The vibration amplitude of each span rotor of multi-span and multi-disk rotor system has not changed, but the vibration balance position has the phenomenon of downward migration, and the X direction deviation of each span rotor is obviously smaller than that of Y direction. On the basis of improving the expression of torque excitation, the effect of elastic coupling on multi-span and multi-disk rotor system is considered, and the torque excitation transfer model of multi-span multi-disc rotor system is established. The sensitivity matrix of bearing load to torque excitation is derived. The different properties of multi-span multi-disk rotor system are studied by simulation and experiment. The results show that different properties (linear and transient) of multi-span multi-disk rotor system are different in X direction and Y direction. The sensitivity of bearing load to torque excitation is different in multi-wheel rotor system. Considering the effect of the initial shaft bending fault on the multi-disk rotor system, the model and dynamic equation of the multi-disk rotor system with initial shaft bending are established, and the initial bending amount is simulated and analyzed. The influence of eccentricity and damping ratio on bending vibration of multi-wheel rotor system is studied. The characteristic extraction and signal identification of the initial shaft bending fault test signal are realized by wavelet and nonlinear popular method. The bending fault signals of the initial axis are compared and analyzed. The experimental correction equation of rotor system with initial shaft bending is proposed. 5) on the basis of wavelet denoising and mathematical morphological de-noising, the wavelet morphological filtering method is proposed. The simulation signal and bearing load test signal are de-noised by morphological de-noising method and wavelet morphological filtering method, respectively. The denoising results show that the wavelet morphological filtering method is effective for bearing load signal de-noising. Through the research in this paper, the influence of torque excitation on multi-span and multi-disc rotor system can be clearly understood, and the characteristics of torque excitation transmission, initial shaft bending fault signal and bearing load signal can be more clearly realized. It lays a solid foundation for suppressing the disturbance of torque excitation, diagnosing typical faults of rotor system and improving the efficiency of signal collection in rotor system test.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH113;TH165.3

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