基于模型的转子裂纹时域识别方法研究
发布时间：2018-09-17 14:56
【摘要】：在现代化工业建设中,大型的旋转机械设备被广泛应用在各个领域,转轴上的疲劳裂纹是一类重要的转子缺陷形式,若其不能被及时检测出,将会导致灾难性的后果,因此保证它们安全稳定的运行是十分必要的。 本课题的目的是研究一种在时域上,对在线转子的裂纹位置及深度进行诊断和识别的方法,称为基于模型的转子裂纹时域识别方法。首先需要利用已有的有通过限元法建立的裂纹-转子模型,计算裂纹转子的振动特性；基于模态扩展理论,通过使用有限个自由度上的振动扩展得到全部自由度的振动；运用动力学方程计算等效力,观察裂纹等效力的分布；使用通过刚度的变化得到的理论裂纹模型,计算不同裂纹条件下的理论值；运用最小二乘法,分别对模态扩展得到的等效力的测量值,与通过理论裂纹模型得到的理论值,进行比较和筛选,找出最可能出现裂纹的位置跟深度,最后通过验对结果进行了讨论和验证。
[Abstract]:In modern industrial construction, large rotating machinery is widely used in various fields. The fatigue crack on rotating shaft is an important form of rotor defect. If it can not be detected in time, it will lead to disastrous consequences. Therefore, it is necessary to ensure their safe and stable operation. The purpose of this paper is to study a method to diagnose and identify the position and depth of a rotor crack in time domain, which is called a model-based method for rotor crack identification in time domain. Firstly, the vibration characteristics of cracked rotor should be calculated by using the existing crack-rotor model established by finite element method, and the vibration of all degrees of freedom can be obtained by using the vibration propagation on finite degrees of freedom based on modal expansion theory. Using the kinetic equation to calculate the equal force, observe the distribution of the equal force of the crack, use the theoretical crack model obtained by the change of stiffness, calculate the theoretical value under different crack conditions, use the least square method, The measured values of equal force obtained by modal propagation and the theoretical values obtained by theoretical crack model are compared and screened to find out the most likely location and depth of cracks. Finally, the results are discussed and verified by a test.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3
本文编号：2246270
[Abstract]:In modern industrial construction, large rotating machinery is widely used in various fields. The fatigue crack on rotating shaft is an important form of rotor defect. If it can not be detected in time, it will lead to disastrous consequences. Therefore, it is necessary to ensure their safe and stable operation. The purpose of this paper is to study a method to diagnose and identify the position and depth of a rotor crack in time domain, which is called a model-based method for rotor crack identification in time domain. Firstly, the vibration characteristics of cracked rotor should be calculated by using the existing crack-rotor model established by finite element method, and the vibration of all degrees of freedom can be obtained by using the vibration propagation on finite degrees of freedom based on modal expansion theory. Using the kinetic equation to calculate the equal force, observe the distribution of the equal force of the crack, use the theoretical crack model obtained by the change of stiffness, calculate the theoretical value under different crack conditions, use the least square method, The measured values of equal force obtained by modal propagation and the theoretical values obtained by theoretical crack model are compared and screened to find out the most likely location and depth of cracks. Finally, the results are discussed and verified by a test.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3
【参考文献】
相关期刊论文 前2条
1 于涛;韩清凯;孙伟;闻邦椿;;基于模态扩展与谐波分解的转子碰摩故障精确诊断[J];东北大学学报;2006年05期
2 姚红良;王月;李小彭;闻邦椿;;耦合故障转子系统中裂纹信息的诊断[J];应用力学学报;2007年02期
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