Kinematic modelling of 3D woven fabric deformation for structural scale features

Abstract

A multi-scale approach to modelling is optimal for computationally intensive problems of a hierarchical nature such as 3D woven composites. In this paper an approach capable of modelling feature/component scale fabric deformations and defects is proposed. The proposed technique starts with a meso-scale model for predicting the as-woven geometry of a single unit cell using a high fidelity digital element method. The unit cell geometry is then converted into a macro-scale fabric model by geometric reduction then tessellation. On the macro-scale, two and three dimensional approaches to yarn geometry representation are proposed, with an accompanying yarn mechanical model. Each approach is evaluated based on solution accuracy and computational efficiency. The proposed approach is then verified against experimental results on the meso and macro scales. The applicability of this modelling technique to larger scale compaction problems is then investigated. The proposed algorithm was found to be accurate and computationally efficient.

Internal geometric modelling of 3D woven composites: A comparison between different approaches

“…During the conversion process the yarn surfaces defined by multiple chains of elements must be detected and converted to TexGen geometric representations as specified in [23]. The DEM geometry of the RVE modelled in TexGen is shown in Fig.…”

“…The geometry obtained by assuming the default parameters in TexGen or WiseTex can be included within this category. The second category is more realistic as the internal geometry of the material is obtained by different modelling techniques, both analytical, such as the geometric model proposed by Isart et al [14], and numerical, such as the Digital Element Method, [22,23,25]. The Digital Element Method geometry and the analytical geometry take part of this second group.…”

“…The results of this study were compared with CT-scans of a dry fabric specimen subjected to in situ compaction. In combination with this technique, El Said et al [23] proposed a single surface approach based on the Digital Element Method (DEM) [24], which is capable of modelling feature/component scale fabric deformations and defects. Feature/components with complex geometries cannot be modelled by RVE.…”

Modelling 3d Woven Composite Preform Deformations

“…In order to be able to model deformation of woven fabrics at a structural feature scale, that includes explicit definition of the individual yarn paths, a simplified representation is required. For this, an approach is adopted using a single contact surface for each yarn, built from shell elements for model size reduction and more efficient contact algorithms [24]. In order to capture the fabric behaviour with a reduced geometry, special care needs to be given to the yarn mechanical modelling.…”

Quantification of mesoscale variability and geometrical reconstruction of a textile

“…In order to take bundle shape changes into account when compacting the fabric in a mould tool, 40 the generated TexGen model of the uncompacted fabrics can then, for example, be used in compaction models to predict bundle deformations. 41,42 …”