3D Woven Fabrics Research Articles

An exposition of shear thickening fluid treated double and 3D woven fabrics with a new integrity factor for enhanced impact resistance

Impact behaviour of a woven fabric depends on its material composition, interlacement pattern (weave) and sett. In this work, 2D and 3D woven fabrics were prepared and evaluated for their impact resistance in neat and shear thickening fluid (STF) treated conditions. 2D structures included homogeneous ultra-high molecular weight polyethylene (UHMWPE) fabric, hybrid fabric of p-aramid and UHMWPE, and double fabric with p-aramid as face and UHMWPE as back layer. 3D woven fabrics of different variants were composed of UHMWPE as warp and p-aramid as weft. A new parameter, named integrity factor, was introduced to quantify the firmness of 3D woven fabrics . The results highlighted the superior impact resistance of neat double fabric, a structure that has not been explored before, and STF treated hybrid 2D fabric. Among the 3D fabrics, impact energy absorption was the highest in through-thickness orthogonal (0.0935 J m2 g−1; integrity factor of 1.760), followed by layer by layer orthogonal (0.0685 J m2 g−1; integrity factor of 1.493) and the least of all, in through-thickness angle interlock fabric (0.0373 J m2 g−1; integrity factor of 1.026). STF treatment improved the impact resistance in all cases of 2D, double and 3D fabrics, with increment ranging from 38 to 153%. Outcome of this research will be helpful in designing double and 3D woven fabrics for impact resistance applications.

Effect of the stuffer yarns on the mechanical performance of novel 3D woven green composites

Determination of mechanical properties of 3D woven reinforcements is crucial for tailoring the required properties for end application. The current study presents an investigation of the mechanical performance of novel 3D woven composites’ structures. Various 3D woven fabrics with variation in stuffer yarn density were designed, produced and their mechanical properties such as tensile, shear, drop weight impact and compression after impact were investigated. Reinforcements were developed on a modified Dobby loom from flax yarn with four different levels of stuffer yarn densities. Machine modification ensured controlled amount of tension during reinforcement production for similar sets of yarns with similar crimp percentage. Composites were fabricated using these 3D woven fabrics as reinforcement and green epoxy as a matrix. It was observed that the impact and flexural properties are significantly improved by increasing stuffer yarn density.

Experimental Study of Mechanical Behavior of 3D Angle-Interlock Woven Fabrics under Cyclic Load

During the formation of complex shapes, textile reinforcement is subjected to large local and global deformation, which affects the quality of the final composite product. This study investigated the deformation behaviors of 3D angle-interlock woven fabrics, which were used in their "dry state". Hence, both cyclic tensile tests and picture-frame type of shear tests were performed to compare the deformation processes. The results showed that the shear cyclic displacement condition produced a higher shape-preserving ability than its tensile counterpart. In addition, the negative Poisson’s ratio in the thickness direction was observed only when the tensile displacement was applied along the warp direction. A theoretical model was presented to predict the thickness variations of the woven fabrics and the results agreed well with the experiments.

Dynamic Impact Surface Damage Analysis of 3D Woven Para-Aramid Armour Panels Using NDI Technique.

The effects of the yarn composition system inside 3D woven high-performance textiles are not well investigated and understood against their final ballistic impact behaviour. The current study aims to examine the ballistic impact performances of armour panels made of different 3D woven fabric variants through postmortem observations. Four high-performance five-layer 3D woven fabric variants were engineered based on their different warp yarn compositions but similar area density. A 50 × 50 cm2 armour system of each variant, which comprises eight nonbonded but aligned panels, namely, 3D-40-8/0 (or 8/0), 3D-40-8/4 (or 8/4), 3D-40-8/8 (or 8/8) and 3D-40-4/8 (or 4/8), were prepared and moulded to resemble female frontal morphology. The armour systems were then tested with nonperforation ballistic impacts according to the National Institute of Justice (NIJ) 0101.06 standard Level-IIIA. Two high-speed cameras were used to capture the event throughout the test. Nondestructive investigation (NDI) using optical microscopic and stereoscopic 3D digital images were employed for the analysis. The armour panels made of the 8/0 and 4/8 fabric variants were perforated, whereas the armour made of the 8/8 and 8/4 fabric variants showed no perforation. Besides, the armour made of the 8/4 fabric variant revealed higher local and global surface displacements than the other armours. The current research findings are useful for further engineering of 3D woven fabric for seamless women’s impact protective clothing.

Numerical and experimental investigation on 3D angle interlock woven fabric under ballistic impact

3D woven fabric has great potential applications in body armor due to its good mouldability. This paper reports the ballistic mechanism of 3DAWF under the Full Metal Jacket (FMJ) projectile impact. Numerical simulation of 3DAWF under ballistic impact employing strain rate effect material models was established to capture the yarns’ behaviors under high-speed impact loadings. Membrane elements construct a full-size mesoscale model based on real 3DAWF structure to improve computational efficiencies. The ballistic impact tests of 3DAWF subjected to the FMJ projectile were carried out to validate and evaluate the finite element analysis (FEA) model. From the results of the tests and theoretical model, it was found that the FEA model exhibits a relatively good correlation with tests on residual velocities, deformation, and damages. This work revealed the impact damage evolution, energy absorption mechanism, and the stress wave distribution in the 3DAWF, and the findings are instructive for the design of 3DAWF for ballistic protection.

Development of 3D hollow woven fabrics with superior mechanical properties by using nitinol and steel wire core hybrid yarns

In this study, nitinol and steel wire core hybrid yarns were produced from wires having two different diameters and used as warp yarns to weave 3D woven fabrics in two different fabric constructions. The steel bars with two different diameters were placed into the gaps between fabric layers to create a hollow form after fabric production. The fabrics produced with cold-worked nitinol wire were exposed to heat treatments at high temperatures to provide them shape memory property according to data obtained from DSC analysis. Conventional textile fibers are not durable to these temperatures; for this reason, carbon fiber was used both as sheath material of hybrid yarns and additionally as warp and weft carbon fiber yarns. All yarn and fabric tests were carried out simultaneously to evaluate the mechanical properties of nitinol and steel wire core hybrid yarns, and wire-reinforced fabrics. Tensile tests were applied to all wire and hybrid yarn samples, DSC and DMA analyses were conducted for only heat-treated nitinol wires. Low-velocity impact, tensile and pull-out tests were applied to fabric samples. Reference fabrics with no wire were produced and evaluated by comparing with wire-reinforced samples to provide a point of comparison to the data from the mechanical properties of wire-reinforced 3D fabrics. The study's results were analyzed with regression analysis using the backward method, and the parameters such as wire type, wire diameter, and fabric gap width for optimum fabric production were determined. Data obtained from all mechanical tests demonstrate that fabric samples with steel wire, thinner wire, and narrow gaps have better results than others. The effect of wire thickness was also found the same for the nitinol wire. DMA analyses show that the thinner nitinol wire is better than, the thicker one. Finally, an innovative technique has been developed in this study to weave carbon fiber on a conventional automatic sample loom without fiber breakage by twisting PVA yarn around the wire core hybrid and twisted carbon fiber yarns.

Numerical Analysis of Binding Yarn Float Length for 3D Auxetic Structures

Recently, the auxetic fabrics have gained much importance in the scientific and industrial community due to their excellent impact‐resistance property. Due to this property, they have several applications, including automotive, aerospace, and ballistic areas. The auxetic three‐dimensional (3D) woven fabrics are a less explored domain in the auxetic community. Herein, special attention is given to the numerical analysis of the 3D auxetic structure. The negative Poisson's ratio of 3D auxetic structures is studied using ANSYS workbench structural analysis module. The effect of binding yarn float length on negative Poisson's ratio is tested on ten different 3D orthogonal through the thickness structures with binding yarn float length of 1:1, 2:1, and 3:1. Furthermore, the effect of the number of binding yarns and the number of layers is also studied numerically. The results show that the auxeticity of the woven structure increases with increasing the number of binding yarns and their float length. Moreover, decreasing the number of layers from 3 to 1 increases the auxeticity.

Development of 3D auxetic structures using para-aramid and ultra-high molecular weight polyethylene yarns

In recent times, auxetic woven structures gained considerable attention from the researchers due to their excellent impact properties in high-performance areas. Researchers have done much work on the auxetic behavior of the natural and low-performance yarns in two-dimensional structures. Keeping in view the structural application of auxetic structures, in this work, three-dimensional (3D) woven auxetic fabrics were developed on conventional weaving machines with high-performance yarns. Effect of high-performance yarns (Para-aramid and UHMWPE) as the main structure and binding threads on the auxeticity of 3D fabric structures and the impact properties of their corresponding composites were discussed. For this purpose, eight different orthogonal 3D woven structures were produced with para-aramid filament yarn as warp and weft, whereas ultra-high molecular weight polyethylene (UHMWPE) filament yarn was used as a binder. The tensile load was applied to the 3D fabrics to check their auxeticity, and a change in thickness was recorded. The results showed that as the float length of binder yarn and warp yarn increases with the equal and same ratio, the auxeticity also increases. While auxeticity decreases as the difference between the float length of binder yarn and warp yarn increases. The Negative Poisson's Ratio (NPR) of 3D woven fabrics ranged from −0.9 to −2.98. In the second step, these 3D woven fabrics were fabricated into their composites using unsaturated polyester resin, and the hand-layup technique. Their impact strength was measured using the Charpy test method. Auxetic woven composites made of high-performance yarns structures showed impact strength ranging from 55.64 kJ/m2 to 158.46 kJ/m2. Highlights High-performance yarns (Para-aramid and Ultra-high molecular weight polyethylene) were used to create eight 3D woven and composite samples with enhanced auxetic behavior. The result shows that samples having maximum binding yarn float length and fewer intersection points show maximum auxeticity and increased energy absorption. The maximum auxeticity and impact energy absorption obtained was -2.98 and 158.46 kJ/m2, respectively. The current research has applications in protective textiles and bulletproof composite panels.

Review on the fatigue properties of 3D woven fiber/epoxy composites: testing and modelling strategies

3D woven fiber/epoxy composites as structural components have attracted great attention in the industrial and civil fields due to high resistance to debonding or delamination. Structural components are often subjected to the conditions of cyclic loading, which detrimentally affect the service-life and damage tolerance. In this research, the fatigue properties of 3D woven fiber/epoxy structural composites were discussed, where 3D woven fabrics were embedded in epoxy matrix to enhance their mechanical properties. 3D woven fabrics were classified by the geometrical structures of repeat vertical and inclined units. Based on the testing method, the fatigue properties of corresponding composites have been reviewed. The influence of the internal and external parameters on the fatigue properties were investigated by using various observation methods, and the failure modes were also analyzed. The theorical prediction models were reviewed according to testing method, and future trends and challenges were discussed. The critical review can provide valuable ideas and guidance for future fatigue studies in 3D woven composites.

Effect of reinforcement architecture on the macroscopic mechanical properties of fiberous polymer composites: A review

AbstractIn order to curb the fuel consumption and corresponding CO2 emission, defence, automobile, and aerospace industries are leaning towards the use of light weight‐high stiffness engineered materials like fiber reinforced polymer composites (FRPCs). One of the major advantages of FRPCs is that various properties (stiffness, tensile strength, flexural strength, etc.) can be tailored according to requirements of the application. Architecture of the reinforcement used in FRPCs has been proved to affect these properties substantially. Composite materials have seen a lot of advancement in the field of reinforcement architectures starting from the plain‐woven fabrics to advanced 3D braided/woven preforms. The architecture of reinforcement must be wisely selected to design the required properties of developed composites and to reduce the overall cost without compromising the performance. The problem addressed in the present study is the selection of reinforcement architecture while developing a composite material. 2D Plain woven reinforcements are better than other reinforcements in terms of in‐plane properties but their out‐of‐plane properties are very poor. Therefore, advanced architectures like 3D woven fabrics, 5D Braided preforms, knitted preforms, and 3D needle punched fibers are being used in various high performance applications. The present article is an attempt to analyse the effect of various available architectures of reinforcement on the macroscopic mechanical properties of FRPC laminates and to propose a systematic way to select a reinforcement.

100% PVDF 3D textiles structures to improve energy harvesting

With a final view to prototyping a textile energy harvesting system, piezoelectric textile structures based on 100% poly(vinylidene fluoride) (PVDF) were developed and characterized. Multifilaments of 246 tex were produced by melt spinning. The mechanical stretching during the process provides PVDF fibers with an optimal β-phase ratio (97%). Some studies have already been carried out on piezoelectric PVDF-based structures as films or textiles. The goal of the study is the investigation of the differences between 2D and 3D woven fabrics structures from piezoelectric PVDF multifilament yarns. The textile structures were poled after the weaving process, and a maximum output voltage of 2.3 V was observed on an angle - through-the-thickness interlock (interlock 3D structure) under compression by DMA tests. Energy harvesting is optimized in a 3D interlock thanks to the stresses of the multifilaments in the thickness. This finding has led to the design of an inner sole prototype from a knitting structure and another structure with piezoelectric fibers outside the plane of the fabric. The prototype is able to harvest energy and the results are consistent with the measurement realized with DMA under dynamic compression close to walking.

BENDING PROPERTIES OF 3D I-SHAPED WOVEN COMPOSITES

This paper deals with the bending properties of 3D (three-dimensional) basalt reinforced I-shaped woven composites with epoxy vinyl resin. The 3D I-shaped woven fabrics with three different heights were fabricated on ordinary loom by reasonable design with low cost. The 3D I-shaped woven composites were fabricated by VARTM（vacuum assisted resin transfer molding）process.The bending tests were conducted on a microcomputer control universal testing machine (TH-8102S). The Load-displacement and energy-displacement scatter plots were obtained from experimental tests.The result showed that the polynomial fitting formula can be obtained by the calculation of least square method in the software of origin 8.0. Through the analysis of the mathematical equation and correlation coefficient of load-displacement and energy-displacement relationship, it could be seen that the fitting effect of the curve was better. This mathematical equation of this method can be used to predict the relationship between load, energy and displacement.

Prediction of residual mechanical properties in flexure-after-impact of woven composite beams through electrical resistance measurement

Low-velocity impact and flexure-after-impact (FAI) tests were performed on 2D plain woven fabric (PWF) and 3D orthogonal woven fabric (OWF) reinforced carbon fibers/epoxy composite beams while the electrical resistance measurement was applied during impact and FAI tests via four-probe technique to study the relations between resistance variation (RV) and residual mechanical properties. The impact tests (from 3 J to 9 J) showed that OWF specimens have better suppression of delamination than PWF, which was also evaluated through thermography and cross-sectional imaging method. Then FAI tests were implemented on impacted specimens while acoustic emission signals were captured. The residual flexural strength and modulus from the FAI tests were normalized by the values of intact specimens and compared with the RV from impact tests. The relations between electrical and mechanical properties revealed that the rise of resistance after the impact is an effective sign that indicates the reduction in the residual flexural strength and modulus of the composite beam. Moreover, the relation between RV and residual modulus is more effective than that with residual strength.

Transverse compaction of 2D glass woven fabrics based on material twins – Part I: Geometric analysis

In Liquid Composite Molding (LCM), compaction of the reinforcement occurs during several stages of the entire process, including before and during resin injection, which leads to significant deformation of the fibrous architecture. This affects not only the manufacturing process, but also the mechanical properties of final parts. This article aims to study by X-ray microtomography the mesoscopic deformations of 2D glass woven fabrics under transverse compaction for a range of fiber volume fractions encountered in high performance composite applications. The analysis is based on the recently proposed Micro-CT Aided Geometric Modeling (AGM) technique Huang et al. (2019) [1], which is used to create, from the three-dimensional images of dry textile preforms obtained by microtomography, “material twin” geometric models representative of fiber architecture. Three “material twin” mesostructural geometric models of a stack of multiple layer 2D woven fabrics are generated from microtomographic images at different compaction levels. Since all the fiber tows are reconstructed from real fabrics and are labeled separately, the deformation and displacement of fiber tows during compaction can be subsequently studied, which is not necessarily possible with other reconstruction methods. The results show that contacts between fiber tows have an effect on the evolution of their morphological features, which is related to the material variability of fiber tows in real fabrics. Tracking of the fiber tows positions also reveals that the vertical displacement of fiber tows are significant, while their horizontal movements are negligible.

3D network structure and sensing performance of woven fabric as promising flexible strain sensor

A flexible strain sensor was developed through weaving conductive yarns to 3D woven fabric. The relationship between the sensing performance of the woven fabric and its 3D network structure containing yarn shrinkage and arrangement density, as well as fabric interweaving, was investigated according to Pierce’s fabric geometry model and the assumption of elastic strain of yarn. Based on such models and assumption, the theoretical results were verified by the experimental data from uniaxial stretching, and the trends of both results were consistent. The sensitivity of woven fabric on its elastic strain is relatively small (GF < 2) and nonlinearity. With the deformation of fabric geometry structure (Stage I) caused by stretching on warp direction, the shrinkage of weft yarn (cw) and interweaving points (nw) decreased or the arrangement density of warp yarn (Nj) increased, resulting in improved sensitivity on warp direction. At yarn deformation stage (Stage II), the increase in interweaving points (nw) or the decrease in arrangement density of warp yarn (Nj) could improve the sensitivity on warp direction. All the results provide a theory basis for the design and development of flexible strain sensor with promising application as wearable electronic device.

Non-intrusive proper generalized decomposition involving space and parameters: application to the mechanical modeling of 3D woven fabrics

In our former works we proposed different Model Order Reduction strategies for alleviating the complexity of computational simulations. In fact we proved that separated representations are specially appealing for addressing many issues, in particular, the treatment of 3D models defined in degenerated domains (those involving very different characteristic dimensions, like beams, plate and shells) as well as the solution of parametrized models for calculating their parametric solutions. However it was proved that the efficiency of solvers based on the construction of such separated representations strongly depends on the affine decompositions (separability) of operators, parameters and geometry. Even if our works proved that different techniques exists for performing such beneficial separation prior of applying the separated representation constructor, the complexity of the solver increases in certain circumstances too much, as the one involving the space separation of complex microstructures concerned by 3D woven fabrics. In this paper we explore an alternative route that allows circumventing the just referred difficulties. Thus, instead of following the standard procedure that consists of introducing the separated representation of the unknown field prior to discretize the models, the strategy here proposed consists of proceeding inversely: first the model is discretized and then the separated representation of the discrete unknown field is enforced. Such a procedure enables the consideration of very complex and non separable features, like complex domains, boundary conditions and microstructures as the ones concerned by homogenized models of complex and rich 3D woven fabrics. It will be proved that such a procedure can be also easily coupled with a non-intrusive treatment of the parametric dimensions by using a sparse hierarchical collocation technique.

The effects of the structural parameters of three-dimensional warp interlock woven fabrics with silver-based hybrid yarns on electromagnetic shielding behavior

The main objective of the present study was to investigate the increase in the electromagnetic shielding effectiveness (EMSE) of a set of five variants of three-dimensional (3D) warp interlock woven fabrics containing silver multifilament yarns arranged in a 3D orthogonal grid. The EMSE enlargement as a factor of increasing the quantity of the conductive material per unit area was investigated. The quantity of the conductive material per unit area in a 3D woven fabric can be enlarged by increasing either the yarn undulation or the number of conductive yarn systems, while the yarn density and yarn fineness are fixed. Thus, the binding depth of the conductive warp was gradually increased for the first four variants in order to increase the yarn undulation. Alternatively, the conductive weft system was doubled for the last variant with the aim of increasing the quantity of the conductive component. It should be noted that changing the weave structure requires less effort and energy while keeping the same threading of warps in the reed compared to altering the warp density. The EMSE was measured in an anechoic chamber and the shielding was satisfactory for all the variants in the frequency range of 1–6 GHz (19–44 dB). The results revealed that increasing only 7% of the waviness degree of the conductive warps led to 17% EMSE improvement due to increasing of the conductive yarns through the thickness of the variants. Moreover, no upward EMSE was detected for the last variant, despite the fact that the conductive weft system was doubled.

Out-of-plane permeability of 3D woven fabrics for composite structures

Polymer composites in structural applications commonly provide reinforcement based on 2D textile products, such as woven fabrics or non-crimp fabrics. This leads to sensitivity for delamination and high lay-up effort, especially when a large part thickness is required. 3D woven fabrics (3D-WF) can prevent delamination by incorporating fibers in out-of-plane direction and given the increased areal weight of the single layers, the effort for lay-up is strongly reduced. However, large part thicknesses are also challenging when it comes to impregnation. A high out-of-plane permeability helps facing this challenge. Within this study, the saturated out-of-plane permeability of different 3D-WF (glass fiber) with an areal weight ranging from 1850 g/m2 to 5242 g/m2 was measured. It was found that at an equal fiber volume content of 50% the increase of out-of-plane oriented reinforcement fibers leads to an increasing out-of-plane permeability with increasing areal weight.

The numerical and experimental investigation on low-velocity impact response of composite panels: Effect of fabric architecture

The aim of this study is to characterize and assess the effect of fabric structure on the damage resistance subjected to low velocity impact. Composite panels reinforced by layered unidirectional (LU), layered woven (LW) and 3D orthogonal woven (OW) fabric were prepared respectively and the impact tests were carried out on a low-velocity testbench. Finite element models at yarn-level were established to numerically investigate the material deformation and failure mechanism. The impact tests showed that the OW composite possessed better impact resistance with respect to impact-induced deformation and inelastic energy absorption. The roles of the z-binder have also been identified through comparison of impacted morphology and numerical results. The z-binder serves as cracking trigger due to the weak debonding with resin pocket around it and its zig-zag configuration impedes the growth of delamination by damage deflection. Therefore, the discontinuous resin damage in 3D composite allows the enhancement of impact resistance instead of delamination failure in the 2D panel. In addition, the in-plane interlacement of woven fabric causes that primary yarn breaks in the high stress region and forms a circle damage area, whereas the penetrating cracking along the fiber orientation of superficial layer is induced in the unidirectional composite.

XCT-scan assisted flow path analysis and permeability prediction of a 3D woven fabric

Compaction response and resin flow through a fabric are key characterization parameters in Liquid Composite Molding (LCM) processes. In this study, we present a detailed flow path analysis of a complex 3D woven angle interlock fabric using an in-situ X-ray micro computed tomography (XCT) experimental set-up. The set-up is used to obtain the reinforcement compaction response and three principle permeability values at different thicknesses in a single experiment. The compaction provides real-time features of inter-tow gaps, as well as elongation/spreading of weft and warp tows associated with a through-thickness deformation of the binder yarn. The reduction of the pore network during compaction is analyzed through pore size distribution using a granulometry and percolation path analysis. The resin flow path and reinforcement permeability in principle directions are predicted through vigorous digital flow simulations using several computational unit cells extracted from the reconstructed 3D models from XCT scans. The resin flow paths and principle permeability values show a very strong dependence on the solid volume fraction of the scanned images. A relationship between the solid volume fraction and permeability is developed using a modified Kozeny-Carman relation. The predicted permeability values were found to be in good agreement with traditional benchmark experimental data, highlighting the utility of this novel technique.