Roughness variability estimation of microscopic surfaces during engineering wear process- Application to total hip implant

This paper proposes a new method to estimate the roughness changes from topographic features of microscopic surfaces during an engineering wear process. We demonstrate that the evolution of the significant upcrossings of surface topography is the most efficient way to estimate the roughness changes associated with the small-scale changes during the time of wear process. The motivation of this work comes from the fact that the surface roughness is, largely, interpolated with many important mechanical and physical phenomena, such as friction, and wear behaviour during the mechanical contact between joined and sliding surfaces. A special application is investigated on UHMWPE (Ultra High Molecular Weight Polythene) components involved in total hip implants. The aim is to understand the in-vitro wear mechanism of the UHMWPE surface by estimating its roughness evolution.