Maximum micro-slip in tangential contact of randomly rough self-affine surfaces
Maximum micro-slip in tangential contact of randomly rough self-affine surfaces
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DOI：
10.1016/j.wear.2013.11.050
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发表时间：
2014-01-15
期刊：
影响因子：
5
通讯作者：
Popov, Valentin L.
中科院分区：
文献类型：
--
作者：
Grzemba, Birthe;Pohrt, Roman;Popov, Valentin L.
许多先进的摩擦定律包含一个特征长度参数，定义了从粘附到滑动的过渡。然而，这个长度的物理意义和缩放特性还不能澄清。在本文件中，使用的事实是，任何切向接触的弯曲或粗糙表面的机构自然显示在微观尺度上的初步滑动。即使摩擦力可以用最简单的库仑定律局部描述，而没有初始的微滑移，这也是正确的。这被认为是粘滑转换的主要物理机制。在此假设下，可以从理论上预测初始微滑移的特征长度值。本文基于自仿射分形表面接触力学的最新进展，估计了此类表面的特征滑移距离。我们表明，在低法向力，初步滑移显示不依赖于系统的大小，但只对所施加的法向力。对于具有长波长滚降或截止的随机粗糙表面的特殊情况，初始滑移长度具有均方根粗糙度乘以摩擦系数的数量级。(C)2013爱思唯尔有限公司版权所有。
Many advanced laws of friction contain a characteristic length parameter defining the crossover from sticking to sliding. The physical sense and the scaling properties of this length, however, could not yet be clarified. In the present paper, the fact that any tangential contact of bodies with curved or rough surfaces naturally shows a preliminary slip at the micro scale is used. This is true even if the friction can be described locally by the simplest Coulomb law without preliminary micro-slip. This is suggested as the main physical mechanism for crossover from sticking to sliding. Under this assumption, it becomes possible to theoretically predict the value of the characteristic length of preliminary micro-slip. In this paper, based on recent advances in contact mechanics of self-affine fractal surfaces, the characteristic slip distance for such surfaces is estimated. We show that at low normal forces, the preliminary slip shows no dependence on the system size but only on the applied normal force. For the special case of randomly rough surfaces with a long wavelength roll-off or cut-off the preliminary slip length has the order of magnitude of the rms roughness multiplied with the coefficient of friction. (C) 2013 Elsevier B.V. All rights reserved.