Lubricated soft normal elastic contact of a sphere: a new numerical method and experiment
Lubricated soft normal elastic contact of a sphere: a new numerical method and experiment
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球体润滑软法向弹性接触：一种新的数值方法和实验
DOI：
10.1039/d1sm01654g
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Hui, Chung-Yuen
中科院分区：
文献类型：
--
作者：
Liu, Zezhou;Dong, Hao;Jagota, Anand;Hui, Chung-Yuen
润滑中的一个重要问题是在正常接触下挤压刚性球体和弹性基底之间的薄液膜。该问题的数值求解通常使用迭代技术。迭代方案的一个困难是，在负载越来越重的情况下，收敛变得越来越困难。在这里，我们设计了一个不涉及迭代的数值方案。相反，在每个时间步都解决线性问题。该方案全自动、稳定、高效。我们通过解决松弛测试来说明该技术，其中刚性球形压头快速与由液膜润滑的厚弹性基材正常接触。随着压力的减弱，球体被固定到位。我们还在不同条件下对润滑的软 PDMS（聚二甲基硅氧烷）基材进行了松弛实验。这些实验与数值解非常吻合。
An important problem in lubrication is the squeezing of a thin liquid film between a rigid sphere and an elastic substrate under normal contact. Numerical solution of this problem typically uses iteration techniques. A difficulty with iteration schemes is that convergence becomes increasingly difficult under increasingly heavy loads. Here we devise a numerical scheme that does not involve iteration. Instead, a linear problem is solved at every time step. The scheme is fully automatic, stable and efficient. We illustrate this technique by solving a relaxation test in which a rigid spherical indenter is brought rapidly into normal contact with a thick elastic substrate lubricated by a liquid film. The sphere is then fixed in position as the pressure relaxes. We also carried out relaxation experiments on a lubricated soft PDMS (polydimethysiloxane) substrate under different conditions. These experiments are in excellent agreement with the numerical solution.