论文标题
纳米化的半分析模型，用于纳米化的摩擦尺度摩擦
A semi-analytical model for the scale-dependent friction of nanosized asperity
论文作者
论文摘要
通过进行分子动力学模拟，研究了与平坦底物相称的纳米球体的摩擦。特别的重点是接触区域内剪切应力的分布。人们注意到，在滑移区域内，随着剪切应力与正常压力的比率，随着接触中心的距离增加，局部摩擦系数在单调上下降。随着横向力增加，滑动区从接触边缘向内扩展。同时，接触边缘处的局部摩擦系数不断降低，而在滑动区和棍子区域之间的划分处几乎保持不变。这些特征与传统的Cattaneo-Mindlin模型的预测明显不同，该模型假设滑动区域内恒定的局部摩擦系数。鉴于此类新功能，分析模型是先进的，并基于众多原子模拟。该模型不仅准确地表征了界面剪切应力，而且还解释了单纳米化垂体的静态摩擦的尺寸依赖性。
The friction of a nanosized sphere in commensurate contact with a flat substrate is investigated by performing molecular dynamics simulations. Particular focus is on the distribution of shear stress within the contact region. It is noticed that within the slip zone, the local friction coefficient defined by the ratio of shear stress to normal pressure declines monotonically as the distance to contact center increases. With the lateral force increasing, the slip zone expands inwards from the contact edge. At the same time, the local friction coefficient at the contact edge decreases continuously, while at the dividing between the slip and stick zones keeps nearly invariant. These characteristics are distinctly different from the prediction of the conventional Cattaneo-Mindlin model assuming a constant local friction coefficient within the slip zone. An analytical model is advanced in view of such new features and generalized based on numerous atomic simulations. This model not only accurately characterizes the interfacial shear stress, but also explains the size-dependence of static friction of single nanosized asperity.
