Physics of Friction

摩擦物理学

基本信息

批准号：
12640374
负责人：
MATSUKAWA Hiroshi
金额：
$ 2.24万
依托单位：
OSAKA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Sliding friction between two solid surface is an important issue in our daily life and has been investigated from ancient age. Investigation of friction in micro and nano scales starts recently and attracts much attention. Frictional phenomena similar to the sliding friction between two solid surface are observed in solids, such as pinning and dynamics of density waves and magnetic flux lattice. These various frictional phenomena have many common properties but also particularities. Physics of these phenomena is not clear even in fundamental aspects.In this research project we studied frictional phenomena of various scales, attempt to understand them in a unified way and make clear the universality and variety of friction by employing effective model suitable to each scale of frictional phenomena. We got the following results.i) We investigated the 2-dimensional model, in which all atoms in one solid are fixed, and obtained the following results.The direction of motion can deviate from … More that of the external force.Randomness can make small the frictional force.The system has a peculiar order, the so called Bragg glass.The system in motion has finite static frictional force against the external force perpendicular to the motion.ii) We developed an effective model, which describes the behavior of the lubricant molecule by means of their density fluctuation. Based on the model we discovered a novel phenomena in which the enhancement of crystal order of the lubricant molecules diminishes the frictional force.iii) Graphite is one of the most important solid lubricants with small frictional coefficient. By numerical simulation of the friction of graphite flakes and graphite substrate we reproduced the small frictional coefficient observed in experiments and made clear its mechanism. We also explained the load-dependence of the frictional force microscope experiment of graphite.iv) Various frictional phenomena can be expressed by elastic manifold model with pinning. The effects of plasticity is, however, can not be taken into account in the model. By detailed analysis of the model which take into account the effects of plasticity, we made clear peculiar behavior of the effects and its mechanism. Less

在我们的日常生活中，两个固体表面之间的滑动摩擦是一个重要的问题，并且已经从古代开始进行调查。最近开始对微观和纳米尺度摩擦的研究开始，引起了很多关注。在固体中观察到与两个固体表面之间的滑动摩擦相似的摩擦现象，例如固定和密度波和磁通晶格的动力学。这些各种摩擦现象具有许多共同的特性，但也具有特殊性。这些现象的物理学即使在基本方面也不清楚。在这项研究项目中，我们研究了各种规模的摩擦现象，试图以统一的方式理解它们，并通过采用适合每个摩擦现象规模的有效模型来清楚的普遍性和摩擦。我们得到了以下结果。模型通过其密度波动来描述润滑剂分子的行为。基于模型，我们发现了一种新型现象，在这种现象中，润滑剂分子的晶体顺序的增强减少了摩擦力。IIII）石墨是具有小摩擦系数的最重要的固体润滑剂之一。通过对石墨片和石墨底物的摩擦的数值模拟，我们在实验中观察到了小的摩擦系数，并清楚了其机制。我们还解释了石墨的摩擦力显微镜实验的负载依赖性。IV）各种摩擦现象可以通过弹性歧管模型和固定来表示。但是，在模型中无法考虑可塑性的影响。通过对可塑性影响的模型的详细分析，我们对效果及其机制进行了明确的特殊行为。较少的