3d Modeling of Dense Packings of Bended Fibers

Abstract

For the simulation of fiber systems, there exist several stochastic models: systems of straight non overlapping fibers, systems of overlapping bending fibers, or fiber systems created by sedimentation. However, there is a lack of models providing dense, non overlapping fiber systems with a given random orientation distribution and a controllable level of bending. We present in this paper the recently developed stochastic model that generalizes the force-biased packing approach to fibers represented as chains of balls. The starting configuration is a boolean system of fibers modeled by random walks, where two parameters in the multivariate von Mises-Fisher orientation distribution control the bending. The points of the random walk are associated with a radius and the current orientation. The resulting chains of balls are interpreted as fibers. The final fiber configuration is obtained as an equilibrium between repulsion forces avoiding crossing fibers and recover forces ensuring the fiber structure. This approach can provide high volume fractions up to 72 %. Furthermore, we study the efficiency of replacing the boolean system by a more intelligent placing strategy, before starting the packing process. Experiments show that a placing strategy is highly efficient for intermediate volume fraction.