Energy dissipation in dry sliding friction

物体在固体表面上滑动时所受到的摩擦力与能量的“耗散”有着内在的联系。这种耗散的发生是因为滑动系统被外力驱动进入非平衡状态。耗散通常使用粘性阻尼项进行经验建模，例如在滑动摩擦的普遍应用的现象学普朗特模型中。作为“降低非平衡系统的复杂性”研究单元的一部分，该项目旨在确定结晶和无序固体干滑动摩擦的分子动力学模拟中的能量耗散途径。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如何被热化。从这个分析，我们建立了一个粗粒度的模型滑动系统。从第一原理系统地得出，这种粗粒度的模型将取代普朗特模型的预测能力，并使设计低摩擦界面。

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.