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Simplified method to estimate the intensity of instability which causes the pattern formation phenomena in contact rotating systems

估计导致接触旋转系统中图案形成现象的不稳定性强度的简化方法

基本信息

批准号：
11650251
负责人：
KONDOU Takahiro
金额：
$ 2.3万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

In many contact rotating systems used in the field of mechanical engineering, a large vibration often occurs in operation along with a spontaneous growth of the deformation of system components, and then a periodic deformation pattern is formed on the peripheral surfaces. Such phenomena are mainly caused by the unstable vibration generated in a linear time delay system, and the stability can be analyzed by obtaining the characteristic roots of the system. However, the analytical method has the weak point that a large number of characteristic roots should be obtained for the certain discussion on the stability of the system, since the time delay system has the countable infinite number of characteristic roots. Moreover, the results are not available for a prevention measure of the phenomena, though a large amount of numerical calculation is required. The following subjects were mainly studied to overcome the above difficulties.1. By applying the concept of modal analysis and a viewpoint … More of energy balance, energy factor was newly introduced for a system with many degrees of freedom. The energy factor represents the intensity of instability for each mode. Moreover, a simplified method to analyze the stability and an optimal design procedure to prevent the pattern formation phenomena were developed by using the energy factor. These methods can give an effective index to prevention measures without obtaining the characteristic roots.2. The simplified method and the optimal design procedure were applied to two practical examples of pattern formation phenomena as the representative of a system with large degrees of freedom. One is a polygonal deformation phenomena of a paper making machine with many rubber rollers, and the other is that of a rubber roller system in which the longitudinal bending deformation of shafts is considered. As the result, it is confirmed that the present methods can be used more effectively than the previous method without the decrease in computational accuracy for the system with large degrees of freedom. Less

在机械工程领域使用的许多接触旋转系统中，随着系统部件变形的自发增长，运行中经常会发生较大的振动，从而在外围表面形成周期性的变形模式。这种现象主要是由线性时滞系统产生的不稳定振动引起的，可以通过获得系统的特征根来分析系统的稳定性。然而，由于时滞系统存在无穷多个特征根，因此在对系统稳定性进行一定的讨论时，需要得到大量的特征根，这是解析方法的缺点。此外，虽然需要进行大量的数值计算，但对于预防措施来说，结果是不可用的。为克服上述困难，主要研究了以下几个方面的课题。通过应用模态分析的概念和一个观点…在能量平衡的基础上，为多自由度系统引入了能量因子。能量因子表示每个模式的不稳定强度。在此基础上，提出了一种简化的稳定性分析方法，并利用能量因子提出了一种防止方向图形成的优化设计方法。这些方法在不需要获得特征根的情况下，可以给出预防措施的有效指标。将简化方法和优化设计方法应用于两个图案形成现象的实例，作为大自由度系统的代表。一种是多胶辊造纸机的多边形变形现象，另一种是考虑轴的纵向弯曲变形的胶辊系统的变形现象。结果表明，对于大自由度系统，在不降低计算精度的情况下，本文的方法比以往的方法更有效。较少