| The contact mechanics of solid bodies with rough surfaces is a topic of great practical importance because it affects, among other quantities, friction, adhesion, wear and heat transfer at the interface between two solids. Calculating pressure distributions in contacts has proven difficult due to the complex, multiscale topographies of real surfaces. Being able to predict the distribution of loads in mechanical components within industrial applications bears potential for an improved design of the components' surfaces. For example, unraveling the contact mechanics of aluminum-silicon alloys used in engines of fuel-efficient, lightweight cars, could constitute a big step towards designing an alloy with a reasonable safety factor to avoid aluminum adhesion and scuffing.;In this thesis we introduce a new multiscale technique recently developed by us for the simulation of rough, semi-infinite elastic solids. With its help, we address open questions concerning contact mechanics. Pressure profiles, pressure distributions as well as areas of contact are calculated for single and multi-asperites interfaces with both idealized self-affine and experimentally-measured topographies. The methodology is also employed to shed light on the contact mechanics of aluminum-silicon alloys. Our numerical results are compared to the predictions of the analytical theories by Greenwood and Persson. We show how the theory by Greenwood is unable to predict the correct contact morphologies while Perssons' theory fails when predicting the pressure tails on individual silicon grains within aluminum-silicon alloys.;Keywords. Contact Mechanics, Molecular Dynamics, Green's Functions, Tribology, Multiscale Techniques, Linear Elasticity, Rough Surfaces. |
