The Effectiveness of Standard Friction Models in Predicting the Behavior of Micropatterned Surfaces

Abstract

Computational modeling methods were used to explore how well the behavior of a surface with a micropatterned array of uniformly shaped and spaced semi-cylindrical ribs, as predicted through a deterministic model, may be represented using a traditional Coulomb-based bulk-effects friction model. The effects of the numerical solution method, contact enforcement method, material damage model, and the number of asperities considered were first examined when the micropatterned ribs were directly included in the computational domain. The tribological behavior, defined as the static and kinetic friction forces and the associated energy dissipated, was then recreated for a comparable smooth-surface system using a Coulomb-based bulk-effects friction model, exploring the influence of user-input parameters such as the friction coefficients. With properly selected bulk-effects model parameters, the tribological behavior could be matched between the two types of models. However, the bulk-effects model could not capture the local and time-dependent effects of the asperity interactions on the force and energy measures, which are important in designing micropatterned surfaces. Through the understanding of the influences on model function that is gained through this work, a means to determine the appropriateness of each of these interface model types in studying particular phenomena of interest is provided.