Contact-friction interactions taking place between internal components of synthetic braided ropes when passing over a sheave are suspected to cause damage and to limit their life-time. A modelling approach based on a finite element simulation at the microscopic scale of these interactions is proposed in order to highlight internal mechanisms responsible for this occurrence of damage and to assess stresses within components of the braid [1]. Elementary filaments making up the braided ropes considered in this study are arranged into three successive levels: they are first assembled into yarns, which are twisted to form strands, which are eventually braided together. As the number of filaments is too high (a few tens of thousand), the proposed modelling starts at the level of yarns and considers ropes made of 84 elementary yarns assembled into 12 strands.