Evaluation of Pre-Sliding Behavior at a Rough Interface: Modeling and Experiment

Abstract

AbstractOne of the main issues in precision engineering is the lack of deep understanding of the pre-sliding behavior at the interface of mating surfaces of positioning mechanisms. In addition to the mechanical properties of the contacting bodies, their surface topography plays a key role in the pre-sliding regime and has a great impact on the frictional stiffness. This paper experimentally evaluates a boundary element method (BEM) model for the pre-sliding behavior at the interface of a smooth silicon wafer and a rough polymeric ball. The polymeric ball is either high-density polyethylene (HDPE) or polyoxymethylene (POM). The experiments are conducted at three different normal loads on five different spots on the wafer. The sliding stroke and coefficient of friction are extracted from experiments to be implemented as inputs to the numerical model. The roughness of the balls is also another input. The numerical and experimental friction hysteresis loops are compared. There is a small difference in the predicted pre-sliding distance from the experiments. The lateral stiffness, calculated at three different points on the pre-sliding regime of friction hysteresis loops, is compared with the Mindlin’s solution and experimental values for both contact interfaces and normal loads.