Finite element simulation of textile materials at the fiber scale

A general approach to simulate the mechanical behavior of textile materials by taking into account all their constitutive elementary fibers and contacts between them is presented in this paper. A finite element code, based on an implicit solver, is develop to model samples of woven fabrics as assemblies of beams submitted to large displacements and developing contactfriction interactions between themselves. Special attention is paid to the detection and modeling of the numerous contacts occurring in this kind of structures. Robust models and efficient algorithms allow to consider samples made of few hundreds of fibers. The unknown initial configuration of the woven fabric is obtained by simulation according to the chosen weaving pattern, providing useful informations on fibers trajectories and tows crosssections shapes. Various loading cases can then be applied to the textile sample, in presence of an elastic matrix, so as to identify its mechanical behavior under different solicitations. Results of simulations performed on coated fabric samples are given to illustrate the approach

A finite element approach of the behaviour of woven materials at microscopic scale

A finite element simulation of the mechanical behaviour of woven textile materials at the scale of individual fibers is proposed in this paper. The aim of the simulation is to understand and identify phenomena involved at different scales in such materials. The approach considers small patches of woven textile materials as collections of fibers. Fibers are modelled by 3D beam elements, and contact-friction interactions are considered between them. An original method for the detection of contacts, and the use of efficient algorithms to solve the nonlinearities of the problem, allow to handle patches made of few hundreds of fibers. The computation of the unknown initial configuration of the woven structure is carried out by simulating the weaving process. Various loading cases can then be applied to the studied patches to identify their mechanical characteristics. To approach the mesoscopic behaviour of yarns, 3D strains are calculated at the scale of yarns, as post-processing. These strains display strong inhomogeinities, which raises the question of using continuous models at the scale of yarns

Une approche pour la simulation numérique des milieux enchevêtrés et des structures tissées

Une approche du comportement mécanique de milieux enchevêtrés par la simulation éléments finis à l'échelle des fibres est proposée dans ce papier. Cette approche, qui repose principalement sur une méthode originale de détection et de prise en compte des contacts entre fibres, permet de traiter des échantillons de quelques centaines de fibres. Des applications à des mileux enchevêtrés généralisés et à des matériaux composites textiles sont présentées comme résultats

Simulation of Frictional Contact Interactions Between Warp Yarns and Heddles Within Jacquard Harness for 3d Weaving

The relative motions between warp yarns and heddles within the Jacquard harness used for 3D weaving induce frictional interactions between these elements which may generate both damage in the yarns and weaving errors. To identify the interaction phenomena taking place within such harnesses, a finite element model, based on an implicit solution scheme [1], is proposed. In this model, all elements involved in the harness (cords, heddles, warp yarns) are represented using finite strain beam elements, and frictional contact elements are automatically created to account for frictional contact interactions. Motions defined by the Jacquard card for the shedding are prescribed as boundary conditions to the upper ends of the heddles. The resultant forces necessary to move the heddles are obtained as results of the simulation. Simulation results for an interlock fabric, with 28 warp yarns, will be presented, showing the forces evolution applied to the heddles over a few dozen consecutive sheddings

Modélisation du comportement mécanique de câbles métalliques

International audienc

Simulation numérique du comportement de milieux fibreux enchevêtrés

National audienceSee http://hal.archives-ouvertes.fr/docs/00/59/28/87/ANNEX/r_ML247501.pd

Numerical Simulation of the Mechanical Behavior of Fibrous Materials at Microscopic Scale

International audienc

Numerical simulation of the mechanical behaviour of woven and non-woven materials

International audienc