Development and Multiscale Characterization of 3D Warp Interlock Flax Fabrics with Different Woven Architectures for Composite Applications

Abstract

Multiscale characterization of the textile preform made of natural fibers is an indispensable way to understand and assess the mechanical properties and behavior of composite. In this study, a multiscale experimental characterization is performed on three-dimensional (3D) warp interlock woven fabrics made of flax fiber on the fiber (micro), roving (meso), and fabric (macro) scales. The mechanical tensile properties of the flax fiber were determined by using the impregnated fiber bundle test. The effect of the twist was considered in the back-calculation of the fiber stiffness to reveal the calculation limits of the rule of mixture. Tensile tests on dry rovings were carried out while considering different twist levels to determine the optimal amount of twist required to weave the flax roving into a 3D warp interlock. Finally, at fabric-scale, six different 3D warp interlock architectures were woven to understand the role of the architecture of binding rovings on the mechanical properties of the dry 3D fabric. The results reveal the importance of considering the properties of the fiber and roving at these scales to determine the more adequate raw material for weaving. Further, the characterization of the 3D woven structures shows the preponderant role of the binding roving on their structural and mechanical properties. Fibers 2020, 8, 15 2 of 14composites. These works showed that the architecture of the reinforcement has a preponderant role on the mechanical properties of the composite.Generally, 3D architectures can be obtained by combining multi-layers of stacked 2D fabric with a through-the-thickness fiber reinforcement, introduced using stitching, z-pining, or tufting technologies [10][11][12]. Another technology is the 3D warp interlock weaving, in which multi-layers of in-plane yarns are bound together by a group of binding warp yarns according to a specific architecture (light blue in Figure 1) [13]. Consequently, in 3D warp interlock weaving, a thick structure is formed without degradation to the in-plane fibers that results from needle insertion through-the-thickness in the stitching and tufting techniques. Moreover, the fiber reinforcement through-the-thickness direction is inserted during the weaving and no further steps are required.ibers 2020, 8,15 2 o

Characterization of Tensile Properties of Cola lepidota Fibers

“…These values are the average of ten IFBT specimens. Fibers volume fractions reached are in the range of those obtained by Samouh et al [50] and Lansiaux et al [51] on IFBT specimens made of sisal and flax yarns with the same resin and same manufacturing method, respectively. Samples manufactured with hackled CL fibers bundles show much lower porosities content than for the samples manufactured from non-hackled CL fibers bundle, which can be attributed to the alignment of the fibers that allows a better impregnation.…”

Identification of the Physical and Mechanical Properties of Moroccan Sisal Yarns Used as Reinforcements for Composite Materials

“…The method consists of making composite samples from sisal yarns and identifying the tensile properties of these samples. Fiber-scale properties are deduced, by inverse computation, thanks to the rule of mixtures [32,33].…”

“…The tensile properties of natural fibers are tested by two methods either with the unit of the tensile test of the fiber or with the back-calculation of the properties of fibers from the results of the impregnated bundles or yarns using the rule of mixtures [30,31]. Lansiaux et al [32] have studied the mechanical properties of flax fibers by the Impregnated Fiber Bundle Test (IFBT) method by varying the twist angle of the flax yarns. The obtained results are similar for a twist angle between 0 and 100 tpm with the modified rule of mixtures taking into account the porosity and orientation of the fibers.…”

Eighty years of composites reinforced by flax fibres: A historical review

“…Other novel reinforcement developments include bi-axial and tri-axial braids [75], 3-D weaving [76],…”