Benchmark exercise on image-based permeability determination of engineering textiles: Microscale predictions
Résumé
As experimental permeability measurements of engineering textiles are not only cumbersome but also exhibit large variability as no standardization method exists currently, numerical permeability prediction is an attractive alternative. It has all the advantages of virtual material characterization, including the possibility to study the impact of material variability and small-scale parameters, which are difficult to evaluate experimentally. This paper presents the results of an international virtual permeability benchmark, which is a first contribution to permeability predictions for fibrous reinforcements based on real 3D images. In this first stage the focus was on the microscopic scale computation of fiber bundles using the same image. A total of 16 participants provided 50 results using different numerical methods, physical variables formulations, flow models, boundary conditions, and permeability identification techniques. The final determined scatter of the predicted axial permeability values (after the elimination of inconsistent results) was found to be smaller (14%) than that of the transverse permeability components (~24%). The dominant effect on the permeability was found to be the boundary conditions applied in tangential direction, the number of sub-domains used in the renormalization approach, and the permeability identification technique, which are isolated and discussed in detail.
Domaines
Matériaux| Origine | Fichiers produits par l'(les) auteur(s) |
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