2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27370A two-dimensional \underline{Frenkel-Kontorova model} under a steady external force is used to study the nonlinear sliding friction between flat macroscopic surfaces with a lubricant layer in between. The nonequilibrium properties of the model are simulated by a Brownian molecular dynamics and results are obtained as a function of temperature and a microscopic friction parameter $η$.16 pages, Latex, to appear in "The Physics of Sliding Friction", Adriatico Conf. (95). (Kluwer Publ.)Condensed MatterMaterials Sciencetext