【作者】 庆光蔚；

【导师】 郭勤涛；

【作者基本信息】 南京航空航天大学 ， 机械设计及理论， 2010， 硕士

【摘要】 支承的动态特性参数对磁轴承-转子系统的动力学性能有十分重要的影响。为了能准确设计系统,提高系统的性能和稳定性,识别磁轴承-转子系统的动态特性参数(支承刚度和阻尼参数)就显得犹为必要。本文围绕支承动态特性参数识别这一主题,尝试两种设计参数型修正方法,基于模型修正程序,最终得到以金属橡胶减振器为二次减振支承的磁轴承-转子系统中磁轴承和金属橡胶环结构两大子结构的动态特性参数。具体研究内容如下:利用有限元方法和软件技术进行了金属橡胶环结构和磁轴承-转子系统的动力学建模。分析比较了分别以弹簧单元和实体单元为核心的金属橡胶环结构的有限元模型,选择更准确的弹簧单元模型用于修正。以有限元方法对含金属橡胶环的磁轴承-转子系统模型进行了动态特性分析。利用模态实验数据,运用复模态有限元模型修正方法对金属橡胶环结构进行动态参数识别,模型修正后模态特征值误差较修正前显著降低,说明了所识别参数的准确性,为改进金属橡胶环结构设计提供了参考依据。研究实现了基于频率响应的模型修正方法,探讨了频响函数频率点选择和残差定义等修正的关键问题。将该方法应用于磁轴承-转子系统,修正后的频响函数与实测频响函数吻合良好,说明此方法能够准确有效地识别出磁轴承的动态特性参数。更多还原

【Abstract】 The dynamic performance of a rotor-magnetic bearings system largely depends on the bearing’s dynamic parameters. It is essential to identify the exact dynamic parameters such as the stiffness and the damping so as to accurately design the bearing system and to effectively improve the rotor system’s performance and stability. In this paper, two methods have been carried out based on model updating on complex bearing system(set metal rubber annuluse as sencondary vibration damper)and a group of identified dynamic parameters of the metal rubber annulus structure and active megnatic bearing have been obtained. Specific studies are as follows:The model of the metal rubber was established using finite element (FE) method with related software technologies. The spring element was performed in model updating since its high accuracy compared to the solid element. The dynamic analysis of the metal rubber which attached in the magnetic bearing system was also included in this work.Based on the data from experimental model analysis (EMA), the radial stiffness and damping parameters of the metal rubber were identified using model updating. That the errors of modal eigenvalues have a clearly decreasing trend indicates the credibility of the identified result which can be useful in the design of metal rubber structure.This research have paid special attention on some key issues including the method of model updating based on frequency response and the selection of the frequency point of the frequency response function and the definition of the residual. The method was applied on magnetic bearing-rotor system. The results show that this method was in perfect agreement with the real frequency response function from EMA. It also indicates that this method can accurately and efficiently identify the dynamic parameters of magnetic bearing system.更多还原