横向振动条件下螺栓连接松动的特征分析与提取

发布时间：2017-12-27 04:02

本文关键词：横向振动条件下螺栓连接松动的特征分析与提取　出处：《机械科学研究总院》2016年硕士论文　论文类型：学位论文

【摘要】：螺栓连接是当前使用最广泛的连接形式之一。然而在使用过程中,长时间的振动工况可能会导致螺栓连接的松动。有研究表明,垂直于螺栓轴线的横向循环载荷是引起松动的重要因素。本文结合国内外研究成果,对横向振动下螺栓连接接触面的滑移特征和松动过程进行了理论分析;研制了横向振动试验机,通过试验进一步研究了横向载荷各因素与螺栓松动特征的关系。本文的主要研究工作和内容包括:首先介绍了横向振动载荷下螺纹连接松动的国内外研究现状,以及信号处理技术在故障特征提取与识别的应用概况。随后,基于横向振动下螺栓连接松动基本理论,对松动过程中接触面的滑移特征进行研究,分析了影响滑移的因素,阐述了横向振动下螺栓连接接触面的滑移过程。接着,根据国标准则和使用要求,研发了用于螺栓连接松动试验的横向振动试验机。利用该设备,对螺栓连接的松动特征做了以下研究:研究横向振动下不同润滑状态对螺栓连接松动的影响。分析螺栓连接松动曲线的阶段性特征,利用接触面滑移理论解释该特征。对螺栓松动曲线进行数值拟合,得到特征参数。分析螺栓连接松动过程中被连接件的振幅特征。研究横向载荷与螺栓连接松动的关系。以上试验研究进一步验证了理论分析。最后,为探索螺栓连接松动特征研究的实际应用,搭建了振动信号采集系统,用于采集螺栓松动过程中被连接件的振动信号。分别利用快速傅里叶变换和小波分析技术对采集到的被连接件振动信号进行处理。在频域上得到了螺栓松动各阶段的频率响应特征,在时频域上,通过小波分解,得出了各尺度能量分布特征,进而完成了螺栓连接松动特征的提取。
[Abstract]:Bolt connection is one of the most widely used forms of connection. However, in the process of use, long time vibration conditions may lead to loosening of the bolt connection. It is shown that the lateral cyclic loading perpendicular to the axis of the bolt is an important factor to cause the loosening. Based on the research results both at home and abroad, the slip characteristics and loosening process of bolted connection surfaces under lateral vibration are theoretically analyzed. A transverse vibration testing machine is developed. The relationship between various factors of lateral load and bolt loosening characteristics is further studied through experiments. The main research works and contents of this paper include: first, the research status of threaded connection looseness under transverse vibration load is introduced, and the application of signal processing technology in fault feature extraction and recognition is introduced. Then, based on the basic theory of bolt connection looseness under transverse vibration, the slip characteristics of contact surface during loosening process are studied, and the factors that affect the slipping are analyzed. The slip process of bolt connection surface under transverse vibration is expounded. Then, according to the standard and requirements of the national standard, a transverse vibration test machine for bolt connection loosening test was developed. Using this device, the following research is done on the loosening characteristics of the bolt connection: the influence of the different lubrication state on the loosening of the bolt connection under the transverse vibration. The phased characteristics of the loosening curve of the bolt connection are analyzed, and the characteristics are explained by the contact surface slip theory. The numerical fitting of the bolt loosening curve is carried out, and the characteristic parameters are obtained. The amplitude characteristics of the connected parts during the loosening of the bolt connection are analyzed. The relationship between the lateral load and the loosening of the bolt connection is studied. The above experimental research further verified the theoretical analysis. Finally, in order to explore the practical application of loosening characteristics of bolt connection, a vibration signal acquisition system is set up to collect vibration signals of connectors during bolt loosening. The vibration signals of the connected parts are processed by fast Fourier transform and wavelet analysis. In the frequency domain, the frequency response characteristics of bolts at various stages were obtained. In time-frequency domain, the energy distribution characteristics of each scale were obtained by wavelet decomposition, and the loosening feature of bolt connection was completed.
【学位授予单位】：机械科学研究总院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH131.3

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