Modelling of contact-friction interactions in entangled fibrous materials

International audienceA finite element model is proposed in this paper to simulate the non linear mechanical behaviour of assemblies of entangled fibres submitted to large transformations. The key point of the model lies in an automatic detection of contact-friction interactions between fibres. In all areas where contact is likely to occur, intermediate geometries are constructed. They provide adapted contact search direction and offer a geometrical support for the building up of contact elements. The fibres are taken into account by an enriched kinematical 3D beam model, formulated in large transformations. Periodic conditions are applied to randomly determined samples of fibrous media. Simulation results for the compression (up to 90 %) of five different random samples, show similar behaviours, and allow the identification of exponents of power laws