Viswanathan Koushik, Chandrasekar Srinivasan
Department of Mechanical Engineering, Indian Institute of Science, Bengaluru 560012, India.
Center for Materials Processing and Tribology, Purdue University, West Lafayette, IN 47907, USA.
Philos Trans A Math Phys Eng Sci. 2022 Sep 19;380(2232):20210339. doi: 10.1098/rsta.2021.0339. Epub 2022 Aug 1.
The question of how soft polymers slide against hard surfaces is of significant scientific interest, given its practical implications. Specifically, such systems commonly show interesting stick-slip dynamics, wherein the interface moves intermittently despite uniform remote loading. The year 2021 marked the 50th anniversary of the publication of a seminal paper by Adolf Schallamach (, 1971), which first revealed an intimate link between stick-slip and moving detachment waves, now called Schallamach waves. We place Schallamach's results in a broader context and review subsequent investigations of stick-slip, before discussing recent observations of solitary Schallamach waves. This variant is not observable in standard contacts so that a special cylindrical contact must be used to quantify its properties. The latter configuration also reveals the occurrence of a dual wave-the so-called separation pulse-that propagates in a direction opposite to Schallamach waves. We show how the dual wave and other, more general, Schallamach-type waves can be described using continuum theory and provide pointers for future research. In the process, fundamental analogues of Schallamach-type waves emerge in nanoscale mechanics and interface fracture. The result is an ongoing application of lessons learnt from Schallamach-type waves to better understand these latter phenomena. This article is part of the theme issue 'Nanocracks in nature and industry'.
鉴于其实际意义，软聚合物如何在硬表面上滑动的问题具有重大的科学研究价值。具体而言，此类系统通常表现出有趣的粘滑动力学，即在均匀的远程加载下，界面仍会间歇性移动。2021年是阿道夫·沙勒马奇（Adolf Schallamach，1971年）发表开创性论文50周年，该论文首次揭示了粘滑与移动分离波（现称为沙勒马奇波）之间的紧密联系。在讨论孤立沙勒马奇波的最新观测结果之前，我们将沙勒马奇的研究成果置于更广泛的背景下，并回顾随后对粘滑现象的研究。这种变体在标准接触中无法观测到，因此必须使用特殊的圆柱形接触来量化其特性。后一种配置还揭示了一种反向传播的双波——即所谓的分离脉冲——的出现。我们展示了如何使用连续介质理论来描述双波及其他更一般的沙勒马奇型波，并为未来的研究提供了方向。在此过程中，沙勒马奇型波的基本类似物出现在纳米尺度力学和界面断裂中。结果是，从沙勒马奇型波中学到的经验教训正在不断应用于更好地理解后一种现象。本文是主题为“自然与工业中的纳米裂纹”的一部分。
