Study on Vibration and Noise Reduction Induced by Friction Force

摩擦力减振降噪研究

基本信息

批准号：
15360121
负责人：
MORISHITA Shin
金额：
$ 6.98万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

This research deals with the vibration and noise reduction induced by the friction between surfaces of elastic structures. It is well known that the friction force may induce self-excited vibration in dynamic systems caused by the apparent negative damping of the system. Once it happens, it is very difficult to reduce the amplitude of vibration and it is sometimes followed by the destruction of the system itself. In the case when there is no destruction of the system, it makes large noise uncomfortable for the people around it. So it is important to study the mechanism of friction vibration to reduce its amplitude and noise.Self-excited vibration and stick-slip phenomena are main target of this study. Though stick-slip phenomenon is usually considered as self-excited vibration, they differ to each other. Stick-slip is typically caused by the difference of static friction force and dynamic one. On the other hand, self-excited vibration is defined to be caused by negative damping of the … More system. It may be confusing that stick-slip phenomena are sometimes found in the dynamic system having equivalent negative damping.In order to avoid the stick-slip phenomena, one of the effective ways is to decrease the difference between the static and dynamic friction force. Automatic Transmission Fluid (ATF) has been developed for this purpose and various kinds of Friction Modifier (FM) are blended. Even applying FM to the system which has the possibility to show the stick-slip phenomena, it may be deteriorated after long interval. When the noise is caused mainly by the out-of-plane vibration of friction plates, it may be effective for noise reduction that the distance from the friction surface to the neutral plane of the plate should be decreased. The best condition is coinciding the two planes each other. This trial was conducted by small size model, and it showed remarkable decrement of amplitude of the friction plates. But it should be noted that the vibration energy was transmitted to the other elastic components of the system, and noise was made by other part of the system. In such cases, the vibration amplitude should be decreased by absorbers.MR fluid is one of the functional fluids, and it has been successfully applied to controllable dampers. The investigators proposed to design MR devices considering the flow patterns of MR fluid in the mechanical components. As described above, one of the best ways for vibration and noise reduction is to apply dampers to the friction system, but the experimental verification of this idea to the system may be conducted in the near future. Less

这项研究涉及弹性结构表面之间的摩擦引起的振动和降噪众所周知，摩擦力一旦发生，可能会由于系统的明显负阻尼而引起动力系统的自激振动。降低振动幅度是非常困难的，有时会导致系统本身的破坏，在系统没有破坏的情况下，会导致周围的人感到不舒服，所以它很重要。研究摩擦振动的机理，以降低其振幅并自激振动和粘滑现象是本研究的主要目标，虽然粘滑现象通常被认为是自激振动，但它们之间存在差异。粘滑现象通常是由静摩擦力的差异引起的。另一方面，自激振动被定义为由系统的负阻尼引起的，有时在具有等效负阻尼的动态系统中会发现粘滑现象，这可能会令人困惑。为了避免针对粘滑现象，有效的方法之一是减小静摩擦力和动摩擦力之间的差异，为此开发了自动变速箱油（ATF），并混合了各种摩擦改进剂（FM）。对于可能出现粘滑现象的系统，间隔时间较长后可能会恶化，当噪声主要是由摩擦片的面外振动引起时，采用摩擦面到中性点的距离最好的条件是两个平面重合，该试验是通过小尺寸模型进行的，结果表明摩擦片的振幅明显减小。振动传递到系统的其他弹性部件，系统的其他部分产生噪声，在这种情况下，应通过减振器来降低振动幅度。MR流体是功能流体之一，已成功应用于研究人员建议设计可控阻尼器。考虑磁流变流体在机械部件中的流动模式的磁流变装置如上所述，减少振动和噪声的最佳方法之一是在摩擦系统中应用阻尼器，但可以对系统中的这一想法进行实验验证。在不久的将来。