A macroscale finite element approach for simulating the bending behaviour of biaxial fabrics

Abstract

A macroscale finite element (FE) model was developed to simulate the forming behaviour of biaxial fabrics, incorporating the effects of bending stiffness to predict fabric wrinkling. The dependency of the bending stiffness on the fibre orientation was addressed by extending a non-orthogonal constitutive framework previously developed for biaxial fabric materials. The nonlinear bending behaviour of a biaxial non-crimp fabric (NCF) with pillar stitches was characterised by a revised cantilever test using structured light scanning to measure specimen curvature, providing input data for the material model. Simulations were performed to replicate the bias-extension behaviour of the NCF material, showing good agreement with experimental data. Wrinkles were observed within the central area of the specimen at low extension, which consequently affect the uniformity of the shear angle distribution in the region where pure shear is expected.

Preforming of non-crimp fabrics with distributed magnetic clamping and Bayesian optimisation

“…Strip displacement was measured using a steel rule. Whilst this method could not evaluate non-linear bending, 21 it did offer an approximate representation for the secondary deformation mechanism in distributed clamping.…”

“…Hence, both membrane and bending properties contribute to the deformation mechanics. To evaluate the bending response, Shirley cantilever tests 18,[20][21][22]44,45 were performed according to BS EN ISO 9073-7; 1998 44 to calculate bending stiffness per unit width G:…”

“…18 Membrane models have the advantage of computational efficiency, but at the detriment of mechanical validity, particularly in forming protocols that include bending, whereas typical shell models overestimate the compressive stiffness. Novel developments to these models include the use of submodelling, 19 coupled elements, 20 laminated shell elements 21,22 and more recently, coupled membrane and bending idealised shell models. 3,[23][24][25] Despite these advances, however, accurate computational models require substantial runtimes, meaning most models cannot be directly applied towards the global optimisation of industrial processes.…”

Dry Textile Forming Simulations: A Benchmarking Exercise

“…This phenomenon cannot be represented by standard 2D shell elements alone. A method using laminated shell elements was implemented in commercial FEA platform to simulate forming of biaxial reinforced knitted fabric in (Döbrich et al, 2014) and non-crimp fabric in (Yu et al, 2020;Yu et al, 2021a). This method requires, two fictitious layers at the outer surfaces of the laminated shell that are used to capture the bending property of the textile; the middle layer of the shell is used to simulate in-plane properties.…”

Interlayer interaction characteristics of multi‐layered plain woven glass fabric in hemisphere forming

“…[8,9] For decades, many researches focused on comprehensively characterizing the fabric deformation to deeply understand the defect generation mechanisms [10][11][12] and to accurately predict forming process by numerical modeling. [13][14][15] Most researches have only been done on the monolayer fabric, but in practical forming process, several layers of fabric are stacked together in a certain direction for meeting the performance goal of composites. Due to distinct ply orientations and forming radiuses for different layers of fabric, the interlayer interaction is inevitably generated among fabric layers in multi-layered fabric forming.…”