A MULTIDISCIPLINARY PLATFORM FOR FUTURE TRIBOLOGICAL MODELLING

几乎所有的工程系统和许多生物系统都包含相互载荷和摩擦的部件，例如机器中的齿轮和轴承以及人类的髋关节和膝关节。这种摩擦不仅会造成摩擦，浪费能源，还会造成磨损和其他形式的表面损伤，导致机器（和人类）停机，需要昂贵的维修和更换。这整个研究领域被称为摩擦学，在追求可持续发展（包括减少二氧化碳排放）和提高我们的生活质量方面都是至关重要的。在摩擦学中，摩擦的影响，如摩擦耗散和磨损，被认为是宏观现象，传统上是通过宏观实验和分析来研究的。然而，它们实际上起源于原子和分子尺度，摩擦产生的严重局部应力导致表面层的重组，而摩擦接触中的润滑剂分子与表面相互作用并保护表面。因此，为了理解和改进摩擦学系统，我们需要一种跨越分子、中观和宏观尺度的方法。这将产生关于摩擦和表面损伤的来源的信息——不需要的现象最好从根源上解决——以及设计宏观部件的能力，如润滑剂、轴承、齿轮、发动机和更换接头，这些部件可以根据需要可靠、高效地运行。为了满足这一需求，拟议的研究将开发和应用先进的技术来模拟所有必要尺度的摩擦接触——表面和润滑剂的原子/分子模拟，由于摩擦而观察表面结构演变的中尺度建模，以及实际摩擦部件（如轴承和发动机）的宏观模拟。这些模拟将通过实验来验证，这些实验也跨越了相同的尺度范围，包括直接观察摩擦接触中的分子。然而，这个项目最关键和创新的阶段将是把所有这些模型连接在一起，形成一个以计算机为基础的软件包。其结果将是一套建模程序，可用于许多不同的方式；例如探索摩擦学现象的起源；优化润滑油表面和材料设计；基于设计和底层原子/分子过程的组合来预测机器的性能。这种方法将为我们提供工具，既可以全面了解摩擦和磨损等摩擦学现象，又可以实现有效的“虚拟测试”，在这种测试中，新的和新颖的设计、润滑剂和表面可以结合起来，并在求助于耗时且昂贵的实验开发之前测试它们的有效性。

Almost all engineering systems and many biological ones contain components that are loaded and rub against one another, such as gears and bearings in machines and hip and knee joints in humans. This rubbing results both in friction, that wastes energy, and in wear and other forms of surface damage that lead to machine (and human) downtime, and the need for expensive repair and replacement. This whole field of research is called Tribology and is pivotal both in the quest for sustainability, including reducing CO2 emissions, and in improving the quality of our lives.In Tribology the effects of rubbing, such as frictional dissipation and wear, are perceived as macroscale phenomena and are traditionally studied by macroscale experiments and analysis. However they actually originate at the atomic and molecular scale, where the severe local stresses produced by rubbing cause restructuring of surface layers, while the molecules of lubricant in rubbing contacts interact with and protect surfaces. Thus to understand and so improve tribological systems we need an approach that spans the molecular, meso- and macro-scales. This will yield both information as to the origins of friction and surface damage - and unwanted phenomena are best tackled at their roots - as well as the ability to design macro-scale components such as lubricants, bearings, gears, engines and replacement joints that operate reliably and efficiently for as long as required.To meet this need, the proposed research will develop and apply advanced techniques to model rubbing contacts at all the necessary scales - atomic/molecular simulations of surfaces and lubricants, meso-scale modelling looking at structural evolution of surfaces due to rubbing, and macro-scale simulations of actual rubbing components such as bearings and engines. These simulations will be validated by experiments that also span the same range of scales, including direct observation of molecules in rubbing contacts. The most critical and innovative stage of this project, however, will be to link all these models together in to a single computer-based package. The result will be a set of modelling programs that can be used in many different ways; for example to explore the origins of tribological phenomena; to optimise lubricant surface and materials design; to predict performance of machines based on a combination of design and underlying atomic/molecular processes.Such an approach will give us tools both to understand in full tribological phenomena such as friction and wear and to enable effective "virtual testing", where new and novel designs, lubricants and surfaces can be combined and their effectiveness tested prior to recourse to time-consuming and expensive experimental development.