Energy dissipation in dry sliding friction

物体在固体表面上滑动时所受到的摩擦力本质上与能量的“耗散”有关。这种耗散的发生是因为滑动系统在外力的作用下进入非平衡状态。耗散通常使用粘性阻尼项进行经验模拟，例如，在通常应用的滑动摩擦的唯象普朗特模型中。作为“降低非平衡系统的复杂性”研究单元的一部分，该项目旨在确定晶体和无序固体干滑动摩擦的分子动力学模拟中的能量耗散路径。我们将计算固体的基本振动模式，并测量它们的激发，以及这些激发在滑动过程中是如何被加热的。在此基础上，我们建立了滑动系统的粗粒度模型。该粗粒模型系统地源自第一性原理，将具有取代Prandtl模型的预测能力，并使设计的低摩擦界面成为可能。

The friction force that an object experiences when sliding on a solid surface is intrinsically linked to the "dissipation" of energy. This dissipation occurs because sliding systems are driven into a non-equilibrium state by the external force. Dissipation is often empirically modeled using a viscous damping term, for example in the commonly applied phenomenological Prandtl model of sliding friction. As part of the Research Unit "Reducing complexity of nonequilibrium systems", this project aims at identifying pathways of energy dissipation in molecular dynamics simulations of dry sliding friction of crystalline and disordered solids. We will calculate fundamental vibrational modes of the solid and measure their excitation and how these excitations are thermalized during sliding. From this analysis, we build a coarse-grained model for sliding systems. Systematically derived from first-principles, this coarse-grained model will have predictive power superseding the Prandtl model and enable the design low friction interfaces.