Numerical Investigation of Multi-scale Characteristics of Single and Multi-layered Woven Structures

Abstract

Resin flow through multi-ply woven fabrics is affected by the fibre orientation and laminate stacking sequence during the impregnation process. This is characterised by permeability, which measures the ability of transferring fluids within a 2D or 3D layered woven fibre architecture (i.e., through a porous medium). The work aims to investigate the feasibility of characterising macro-scale flow permeability via the micro-meso-scale (dual-scale) permeability across and along woven yarns, with different structures of yarn nesting, non-shifting, and ply orientation. The permeability characterisation is performed using Ansys-Fluent software package where textile architectures and resin flow in porous media are simulated. The results show that in- and out-plane permeability of the nested, non-shifted and oriented single-ply woven preforms are different than that corresponding to multi-layered plates, making them only applicable for dual-scale permeabilities. However, with a number of plies in the multi-ply woven fabrics — e.g., 9-ply and 5-ply, for in- and out-of-plane flows, respectively — the dual-scale permeabilities can be extended to macro-flow making them applicable at all scales (multi-scale flow). The calculated in-plane multi-scale permeabilities are then used in the 2D simulations and compared with the analytical solution of the Darcy’s equation, which resulted in a very good agreement.

A Numerical Thermo-Chemo-Flow Analysis of Thermoset Resin Impregnation in LCM Processes

“…It is also important to note that dual-scale pores in fabric structures—see Figure 5 —influence the advancing flow-front during the filling process, as the resin impregnation evolves intra- and inter-tow. This is therefore postulated in the given global permeability value, and such a phenomenon has been thoroughly discussed by the authors in previous related works [ 54 , 55 ]. The created mesh topology is, however, subject to the so-called mesh independence study (see previous numerical works [ 54 , 55 ] for further details), whereby controls for sizing (e.g., element size, growth rate, etc.)…”

“…This is therefore postulated in the given global permeability value, and such a phenomenon has been thoroughly discussed by the authors in previous related works [ 54 , 55 ]. The created mesh topology is, however, subject to the so-called mesh independence study (see previous numerical works [ 54 , 55 ] for further details), whereby controls for sizing (e.g., element size, growth rate, etc.) are required to refine the model until the independent results (e.g., velocity values) of the mesh resolution are reached—with no further effect of mesh on the simulation results.…”

Infusion Simulation of Graphene-Enhanced Resin in LCM for Thermal and Chemo-Rheological Analysis

“…This is followed by meshing, whereupon a mesh-independence study is carried out to acquire appropriate and accurate solutions. For further details, the current authors [55,56] conducted and thoroughly discussed a convergence and grid (mesh) independence study in their previous numerical works. Such an RVE will include open (inter-tow) and porous (intra-tow) regions to quantify a two-scale (micro-meso) fill model that will yield a value representing the macro-scale level of the resin flow.…”

“…The experimental data (of García-Martínez et al [27]) adopted in the present work does not supply exponents values, and hence, they are assumed as 1.5 and 1 for a and b based on the work by Shojaei et al [13]. Fabric Design Parameters [56]:…”

An Overview of the Measurement of Permeability of Composite Reinforcements

“…So as shown in Figure 2 c, micro-void defects are expected. Although it is quite difficult to evaluate this complex dual-scale flow, several works have been conducted to study this phenomenon [ 40 , 41 , 42 , 43 , 44 , 45 ]. In the macro-scale approach, the global flow is considered with an average value of fluid velocity and permeability.…”