浅裂纹转子特性的动态圣维南原理解释

针对转子系统中常见的浅裂纹转子,利用动态圣维南原理对其无法通过信号处理方式进行故障诊断的特性进行了原理解释.根据动态圣维南原理的2个条件:外载荷动态合力为0以及外载荷产生的应力波对系统的远端作用为0,分别对裂纹转子呼吸函数以及转子应力波柱坐标弹性动力学解进行了分析与证明,并给出了浅裂纹转子在各种条件下其动态行为符合动态圣维南原理的准则.研究结果表明,实际工况下的浅裂纹转子大多满足动态圣维南原理的条件,难以通过信号处理的方式提取其裂纹故障特征,需要采用其他手段对浅裂纹进行定期检测或在线监测.

Dynamical Saint-Venant’s Principle Solution for Rotor System with Shallow Crack

This paper is dedicated to the solution of rotor system with common fault shallow crack based on dynamical Saint-Venant’s principle and gives the interpretation of the fact that shallow crack is not detectable via the signal processing method. Analysis and proof are implemented on two prerequisites of dynamical Saint Venant’s principle: dynamical resultant of external load equal to zero and the influence of stress wave produced by external load to distal end equal to zero via breath function and elastodynamics respectively. The criterion for whether rotor system with shallow crack yields to dynamical Saint Venant’s principle is also proposed. It concludes that most practical rotor systems with shallow crack yield to dynamical Saint-Venant’s principle and it is difficult to detect characteristics of the crack by signal processing method. Other means of shallow crack prognosis should be adopted for regular testing or online monitoring of the rotor system.