A Stress-State Dependent Sliding Wear Model for Micro-Scale Contacts

Wear is a complex phenomenon taking place as two bodies in relative motion are brought into contact with each other. There are many different types of wear, e.g., sliding, fretting, surface fatigue, and combinations thereof. Wear occurs over a wide range of scales, and it largely depends on the mechanical properties of the material. For instance, at the micro-scale, sliding wear is the result of material detachment that occurs due to fracture. An accurate numerical simulation of sliding wear requires a robust and efficient solver, based on a realistic fracture mechanics model that can handle large deformations. In the present work, a fully coupled thermo-mechanical and meshfree approach, based on the Momentum-Consistent Smoothed Particle Galerkin method (MC-SPG), is adapted and employed to predict wear of colliding asperities. The MC-SPG based approach is used to study how the plastic deformation, thermal response, and wear are influenced by the variation of the interference between colliding spherical asperities. The results indicate a critical interference at which there is a transition of wear from plastic deformation to brittle fracture. The results also indicate that the average temperature changes linearly with increasing interference values up to the critical interference, after which it reaches a steady-state value.