Wear is well known for causing material loss in a sliding interface. Available macroscopic approaches are bound to empirical fitting parameters, which range several orders of magnitude. Major advances in tribology have recently been achieved via Molecular Dynamics, although its use is strongly limited by computational cost. Here, we propose a study of the physical processes that lead to wear at the scale of the surface roughness, where adhesive junctions are formed between the asperities on the surface of the materials. Using a brittle formulation of the variational phase-field approach to fracture, we demonstrate that the failure mechanisms of an adhesive junction can be linked to its geometry. By imposing specific couplings between the damage and the elastic energy, we further investigate the triggering processes underlying each failure mechanism. We show that a large debris formation is mostly triggered by tensile stresses while shear stresses lead to small or no particle formation. We also study groups of junctions and discuss how microcontact interactions can be favored in some geometries to form macro-particles. This leads us to propose a classification in terms of macroscopic wear rate. Although based on a continuum approach, our phase-field calculations are able to effectively capture the failure of adhesive junctions, as observed through discrete Molecular Dynamics simulations.

众所周知，磨损会导致滑动界面中的材料损失。可用的宏观方法受经验拟合参数的约束，经验拟合参数的范围为几个数量级。尽管分子生物学的使用受到计算成本的严格限制，但最近通过分子动力学已在摩擦学方面取得了重大进展。在这里，我们建议对导致表面粗糙度范围内磨损的物理过程进行研究，在该过程中，材料表面的粗糙之间会形成粘合结。使用变分相场方法的脆性断裂方法，我们证明了粘合剂连接的失效机理可以与其几何形状相关。通过在破坏和弹性能之间施加特定的耦合，我们将进一步研究每种故障机制背后的触发过程。我们表明，大的碎屑形成主要是由拉应力触发的，而切应力导致小的或没有颗粒形成。我们还研究了结点组，并讨论了如何在某些几何形状中促进微接触相互作用以形成大颗粒。这导致我们提出宏观磨损率的分类。尽管基于连续方法，但我们的相场计算能够有效捕获胶粘剂连接处的失效，如通过离散分子动力学模拟所观察到的。我们还研究了结点组，并讨论了如何在某些几何形状中促进微接触相互作用以形成大颗粒。这导致我们提出宏观磨损率的分类。尽管基于连续方法，但我们的相场计算能够有效捕获胶粘剂连接处的失效，如通过离散分子动力学模拟所观察到的。我们还研究了结点组，并讨论了如何在某些几何形状中促进微接触相互作用以形成大颗粒。这导致我们提出宏观磨损率的分类。尽管基于连续方法，但我们的相场计算能够有效捕获胶粘剂连接处的失效，如通过离散分子动力学模拟所观察到的。