Energy Dissipation Due to Surface Asperity: A Micro-scale Study

A moving object on a surface slows down and eventually rests where there is no energy input to the object. In physics, the changes in state are caused by the surface asperity existed between the object and the surface, dissipating kinetic energy of the object. This interpretation is simply summative and does not reflect many micromechanics details associated with the object motion. This paper presents a study on the micromechanics of a single particle travelling on a rugged surface. The micromechanics look into the particle-surface contacting, and resulted energy dissipation of the particle. A discrete element model is developed to mimic the contacting. This model is validated against analytical exact solutions which are developed in terms of Newton’s laws of motion. This study examines some important physical conditions on the contacting and the energy dissipation. An interesting example problem is examined to provide results gained from the two approaches. This research is fundamental in that it re-defines inter-particle friction from the micro-scale perspective. Therefore the research helps predict any particle-based geo-motions, e.g. particles piling, debris flow, and rock falls.