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，在运行中常常会伴随着系统部件变形的自发增长而发生较大的振动，然后在外围表面上形成周期性的变形图案，这种现象主要是引起的。线性时滞系统产生的不稳定振动，可以通过获取系统的特征根来分析稳定性，但该解析方法的缺点是需要获取大量的特征根才能进行一定的讨论。由于时滞系统，影响系统的稳定性具有可数无限个特征根，且需要进行大量的数值计算，但尚无法得到该现象的预防措施。为了克服上述困难，主要进行了以下课题的研究。模态分析的概念和能量平衡的观点，针对多自由度系统新引入了能量因子，能量因子代表了每种模态的不稳定性强度。此外，还提出了一种分析稳定性和稳定性的简化方法。通过使用能量开发了防止图案形成现象的最佳设计程序这些方法可以在不获取特征根的情况下为预防措施提供有效的指标。2．将简化方法和优化设计程序应用于以大自由度系统为代表的模式形成现象的两个实例。一种是具有许多橡胶辊的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橡胶辊系统。结果证实，本方法是可行的。比以前的方法更有效地使用，无需大自由度系统的计算精度降低较少。