Deformation Of Yarns Research Articles

A deformation procedure using position-based dynamics to optimize the geometric model of woven fabrics

Generating realistic three-dimensional (3D) yarn-level models for fabrics has become a significant research topic due to the complexity of fabric structures and the requirement for high-quality models with no interpenetration between yarns. The generation process of idealized geometric models leads to inaccurate descriptions of yarn contact, specifically the interpenetrations and spurious voids between yarns. A geometric optimization procedure was developed to address the defects in the idealized models, involving a series of geometry-driven operations, such as the shrinking and expansion of yarn volume and the straightening of the yarn centerline, to obtain accurate and consistent fabric models for Finite Element Analysis. During the geometric optimization, a method for yarn deformation based on position-based dynamics (PBD) was applied to simulate the real deformation during yarn interweaving, ensuring no interpenetrations between yarns while preserving yarn volume. The accuracy of the model is validated by comparison with the real fabric images. Although the methods involved in the procedure are all geometric, their deformation results have realistic physical effects. In addition, the procedure can be applied to various woven fabric structures.

Enhanced shape memory performance and numerical simulation of knitted‐fabric reinforced polymer composites with weft yarns

AbstractFabric‐reinforced shape memory polymeric composites (SMPC) have shown great potential in the design of intelligent deformation structures. In this work, the weft‐knitted fabric inserted with weft yarns was developed as reinforcement to fabricate the shape memory epoxy polymer (SMEP) composites. The effects of weft yarn, loop density and direction on the shape memory performance of SMPC under different bending radii were experimentally investigated. The results show that the SMPC have good shape fixity ratios and shape recovery ratios of around 98%. As compared with those of SMPCs without inserting weft yarns, the SMPCs with weft yarns have shorter shape recovery time, and the recovery force of SMPCs with weft yarns in the 0° and 90° directions shows an increase of 86.4% and 79.5%, respectively. The recovery force of SMPC improve 3.7 times compared to SMEP. The multiscale models of SMPC were established with basis of the results of micro‐computed tomography scanning of specimens and viscoelastic theory. The surface buckling behaviors of SMEP and SMPC specimens after U‐bending load were discussed. Finally, the deformation of loops and weft yarns of SMPC were analyzed to reveal the shape memory mechanism.Highlights Shape memory polymeric composites (SMPC) with weft yarns has shorter shape recovery time. Recovery force of SMPC with weft yarns was obvious enhanced. Multi‐scale viscoelastic models of SMPC were established. Surface buckling behaviors of SMPC after U‐bending load were revealed.

Decoupling Multiscale Analysis of Textile Composite Considering Deformation of Fiber Yarns during Weaving and Molding

Decoupling Multiscale Analysis of Textile Composite Considering Deformation of Fiber Yarns during Weaving and Molding

Numerical analysis of L-shaped wrinkling behavior of 3D woven preforms based on a novel hybrid element yarn model

Numerical simulation is a key means to evaluate the forming performance of 3D woven preforms (3DWPs). However, the macroscopic continuous model of 3DWPs cannot predict the orientation and deformation of yarns, while the microscopic discrete model is unsuitable for large-size samples forming simulation due to computational constraints. A novel mesoscopic hybrid element yarn model is thus proposed to establish a large-size 3D woven virtual yarn preform (VYP) model and the L-shaped virtual forming simulation model. The L-shaped forming experiment of the 3DWP is designed and executed, and the accuracy of the numerical simulation models is verified from three aspects: the mechanical curve, the sample's macroscopic morphology, and the local meso-structure features. Subsequently, the deformation behavior of the yarn structure inside the 3DWP during the L-shaped forming process is analyzed by combining experimental and simulation results. Furthermore, the effects of the L-shaped angle and chamfer radius on the deformation behavior of the 3DWP are studied, which helps guide the structural design of 3DWPs.

VISUALIZING SPUN YARN DEFORMATION: INSIGHTS FROM OPTICAL INSTRUMENTATION

This article presents a comprehensive analysis of key quality indicators for spun yarns, focusing on yarns with a linear density of T=20 (Ne=30) tex produced on both simple and compact ring spinning machines. Through the utilization of optical instrumentation, various parameters including relative breaking strength (Rkm), strength, elongation at break (E %), and hairiness (H %) were meticulously examined to evaluate yarn quality. The study delves into the assessment of yarn unevenness (CV %) as a crucial quality metric, aiming to provide insights into the deformation characteristics of spun yarns. By employing advanced optical techniques, such as high-resolution imaging and precise measurements, the deformation behaviour of yarns under different spinning conditions is elucidated. The findings shed light on the influence of spinning machine type on yarn quality parameters, revealing nuanced differences in strength, elongation, and hairiness between simple and compact spinning processes. Additionally, the analysis highlights the correlation between yarn deformation and overall yarn quality, emphasizing the significance of understanding deformation mechanisms in optimizing textile manufacturing processes. Through a rigorous examination of these quality indicators, this research contributes valuable insights into the intricate dynamics of spun yarn deformation and its implications for textile production. The utilization of optical instrumentation offers a novel approach to visualize and quantify yarn deformation, providing a deeper understanding of the factors influencing yarn quality and performance in industrial settings.

Ballistic resistance and microwave absorbing properties of a composite made of aramid fabric impregnated with polyethylene glycol and hematite nanoparticles

The ballistic resistance and microwave absorption of a composite of aramid fabric impregnated with polyethylene glycol and hematite nanoparticles was investigated for different hematite concentrations between 0 and 17 wt%. Different damage and energy absorbing mechanisms during ballistic impact were identified: cone formation on the back face of the target, tensile failure of primary yarns and deformation of secondary yarns. In terms of energy absorption, the best results were achieved with 7 wt% hematite, while the smallest depth of penetration (DOP) was observed for a composite with 9 wt% hematite. A scanning electron microscope (SEM) image of the composite with 7% hematite after the ballistic test showed that the main energy absorption mechanism was deformation of secondary yarns. The microwave absorption was measured using the waveguide technique in the frequency range from 8 to 12 GHz. The results showed that the dielectric loss ɛ”/ɛ’ is maximum for a concentration of 3% hematite, while the magnetic loss µ”/µ’ is maximum for a concentration of 11 wt% hematite. A reasonable compromise between ballistic resistance and microwave absorption seems to be a composite with 7 wt% hematite.

Theoretical analysis of research conducted on the assessment of short-time and long-lasting deformation of textile yarns

This article presents an analysis of the studies on short-time and long-lasting deformation of textile yarns. The strength and deformation characteristics of the yarns are inextricably linked. In the textile industry, a lot of experiments have been conducted to study the properties of yarn strength. However, this article mainly contains information such as short-time and long-lasting deformation properties of yarns, deformation detection equipment, and their working principle, deformation properties of mixed fiber yarns, analysis of deformation properties of viscose and polyester fibers under the same load, deformation properties of polyester-wool-spandex blend yarns, regression modeling of deformation properties of yarns obtained from polyester-viscose-regenerated bamboo-cotton fiber blends, textile products studies and comments on recommending yarns with good deformation properties can be found.

Mechanical-electrical coupling behaviors of 3-D carbon fiber angle-interlock woven composites under quasi-static and cyclic tension

Mechanical-electrical coupling behaviors of carbon fiber composites is important to structure health monitoring (SHM). Here, we investigated the mechanical–electrical coupling behaviors of 3D carbon fiber angle-interlock woven composites (3DAWC) under tensile loading. Different loading modes including monotonic, cyclic, and fatigue tests were adopted to find the relationship between electrical resistance and tension damages. We also developed a mechanical–electrical constitutive model to reveal the relationship between internal damage modes and the electrical resistance. The tensile deformation and damage of the 3DAWC lead to the increase of the electrical resistance. The increased range is related to the degree of the deformation, damage, and damage accumulation. The transition point of the electrical resistance change represents the initial point of warp yarn longitudinal damages. The irreversible deformation of warp yarns leads to an increase in resistance after unloading. The stress–strain curve and the resistance vs. strain curve can be obtained simultaneously to reveal the internal structural deformation and inner damage mechanisms.

Failure mechanism of weft-knitted insertion fabric/Surlyn resin flexible composite for stab resistance

In this paper, two kinds of aramid fibers were used to prepare weft-knitted insertion fabrics, flexible Surlyn resin as matrix to prepare reinforced weft-knitted insertion fabrics, the effects of hot-pressing temperature, resin content, pressure and holding time on reinforced weft-knitted insertion fabric were explored. Through lamination and co-curing, the effects of the lamination numbers, preparation methods and lamination sequence on the stab resistance of the multilayer system were studied. The results showed that appropriate hot-pressing temperature, resin content, pressure and holding time can improve the stab resistance by improving the permeability of resin in the fabric. However, over high temperatures, pressure and holding time have a negative impact on the stab resistance or flexibility of the composite; high resin content means higher weight, which is not conducive to human wearing. When the area density is similar, the stab resistance of the co-cured composite is the best, followed by the superposition of single-layer composite, finally is the superposition of film and fabric. Weft-knitted insertion fabrics and reinforced weft-knitted insertion fabrics can dissipate puncture energy through shear force, tensile fracture, friction and deformation of yarn or fabric. In addition, composites also have other energy dissipation pathways such as filament compression splitting, fabric/matrix debonding and matrix delamination.

A revised model of kinematic analysis on in-plane shearing behaviour of biaxial fabrics in bias extension test

The previous kinematic model used to describe the in-plane shearing behaviour of biaxial fabrics in Bias-Extension Test (BET) has a deficiency in which the transverse deformation of yarns is ignored during the yarns compacting phase, making it impossible to precisely calculate the in-plane shear force. This paper not only demonstrated the accuracy of previous kinematic model merely suitable for the relative looser fabrics before the yarns compact, but also proposed a revised kinematic model considering the variation of yarn width to better understand the in-plane shearing behaviour during the yarns compacting. The BET results, which were obtained using two fabrics manufactured from completely different yarns, clearly show that the revised model could provide more credible data in calculating the variation of in-plane shear angle and force than the previous model. In addition, the yarns compacting stress was also studied to understand the transition from yarns compacting to slippage during BET.

Numerical simulation and experiment verified for heat transfer processes of high-property inorganic fiber woven fabrics

Numerical simulation is an effective method to study the heat transfer of fabric. However, the interlaced structure of the woven fabric deforms warp yarns and weft yarns to varying degrees, so it is not easy to obtain an effective model of the fabric and the effective thermophysical parameters of the yarns. In addition, at a high temperature, the anisotropy and temperature-dependent property of the thermal conductivity of the yarn also need to be considered. Therefore, this work established a transient heat transfer simulation model based on the effective woven fabric structure and the effective thermophysical parameters of yarns to study the heat transfer processes of three kinds of high-temperature-resistant inorganic fiber (quartz fiber, high-silica glass fiber and basalt fiber) fabrics at different temperatures (especially high temperature). The fabrics were embedded in epoxy resin and made into slices, and then cross-sectional slices of the woven fabrics were observed through a three-dimensional microscope to construct the fabric geometric models. Taking into account the influence of warp yarn and weft yarn deformations in the fabric structure on the fiber volume fractions and the anisotropic and temperature-dependent property of thermal conductivities of the yarns, the thermophysical parameters of warp yarns and weft yarns in the woven fabrics were optimized. Then the fabrics were simulated for transient heat transfer at different temperatures (373.15, 573.15 and 773.15 K). The simulation results were verified through experiments. The good correlation between the two results proved the effectiveness of the simulation method.

Theoretical and experimental studies for the evaluation of yarn transportation issues and suit thread stiffness in textile industry

Differential equations of thread motion must satisfy initial and boundary conditions as well as holonomic and nogolonomic bonding conditions. Holonomic and nogolonomic bonds lead to the nonlinearity of the differential equations of yarns where the law of deformation is linear. This, in turn, limits the ability to obtain analytical solutions to the differential equations of motion of yarns. Because of this, most studies consider yarns to be an environment that can only resist elongation. Methods of theoretical and experimental research and evaluation of the bending strength of the suit thread material are proposed in this article. Besides that, yarn transportation issues were also discussed according to the loss of yarn deformation. An algorithm for calculating and the results of numerical experimental studies of the dependence of bending deformation on the main deformation parameters of the filament material are presented. The developed methods of theoretical and experimental study of internal forces, bending deformation and bending stiffness coefficient can be used in designing new filament materials and assessing the strength of specified materials.

Off-axial angle sensitivity of 3D orthogonal woven composite failure behavior subjected to in-plane compressive loading

This work investigated off-axial angle effect on in-plane compression behavior of 3D orthogonal woven(3DOW) composite under both quasi-static and dynamic loading. Mechanical responses of 3DOW specimens with different off-axial angles were evaluated using a universal material tester and a split Hopkinson pressure bar(SHPB) testbench. An infrared thermographic camera was used to record temperature rising of the specimens in order to characterize the damage development in quasi-static compression. A yarn-level finite element model considering progressive damage behavior of impregnated yarn, matrix resin and their interface were also established to reveal the deformation behavior and failure mechanism. It is found that the off-axial angle has significant influence on compressive response and failure mode. The modulus and compressive strength of specimens exhibited a decreasing tendency with increase of off-axial angle, while failure strain had a rising trend. In addition, the role of z-yarn was identified in different off-axial angle cases. For on-axial specimen, the z-yarn suppressed out-of-plane deformation of superficial weft yarns failing in kinking mode. It in turn caused intensive z-yarn breakage, which accompanied by high temperature rising. For off-axial specimens, rotation deformation of weft and warp yarns was observed, which was restrained by z-yarn. It leaded to extensive debonding between matrix and yarns and delamination characterized by relative low temperature rising.

Meso-scale modeling and damage analysis of carbon/epoxy woven fabric composite under in-plane tension and compression loadings

The mechanical properties and damage behaviors of carbon/epoxy woven fabric composite under in-plane tension and compression are studied at the meso-scale level through experiment and simulation. An efficient representative volume element (RVE) modeling method with consistent mesh, high yarn volume fraction and realistic geometry is proposed. The material constitutive laws with plasticity, tension-compression asymmetry and damage evolution are established for the three components - yarn, matrix and interface, respectively. Significantly different mechanical properties and damage evolutions are observed depending on loading conditions and initial geometry characteristics. It shows a non-linear stress-strain curve with clear transition region and intensive damage in tension, while a quasi-linear behavior up to facture is observed in compression with little damage prior to final fracture. Moreover, compared to the constant Poisson's ratio with straining in compression, a dramatic increase in Poisson's ratio appears in tension. Simulation shows damage mechanisms including transverse damage, matrix damage and delamination, which all play critical roles in the property evolution. In particular, the rapid damage accumulation after elastic deformation destroys the strong bonds and causes the easy deformation of transverse yarns which results in the transition region and large Poisson's ratio in tension. All the mechanical behaviors and damage evolutions are well captured and explained with the current RVE model.

Exploring the relationship between applied fabric strain and resultant local yarn strain within the elastic fabric based on finite element method

As kinds of unique textiles with high extensibility and elasticity, elastic fabrics are widely used for sportswear, medical textiles and electronic textiles. The tensile behavior of fabric is very important for post-processing and usage of fabric. However, there are very few studies on the resultant yarn strain subjected to the applied fabric extension, which is crucial for understanding the tensile behavior of elastic fabric and expanding its potential applications. In order to address the tensile behavior of elastic fabric, a mechanical model of fabric was built for the analysis of local yarn strain within the fabric through finite element method (FEM). The FEM models with full consideration of the tensile property of elastic yarns were built to predict the relationship between the applied fabric strain and the resultant yarn strain. An experimental study was conducted to characterize the yarn deformation behavior during the fabric stretching and compare with the FEM prediction. The FEM simulations show a good agreement with the experimental results. Based on the FEM models, the effects of fabric structural parameters on such a relationship were investigated for understanding the deformation mechanism and thus optimizing the tensile properties of fabrics. A yarn strain of 27.5% could be achieved under 60% fabric strain by adopting an optimized warp yarn spacing of 0.8 mm. The results not only shed light on the origin of high extensibility and elasticity of fabrics but are of great value to the design and development of elastic materials for various applications such as textile-based electronics.

Investigation of the Friction between Dry and Wetted Carbon Filaments

The friction between carbon filaments has a big impact on the deformation of dry yarns. Therefore, to simulate the deformation of yarns on a microscopic level, it is very important to obtain the true friction coefficient at different boundary conditions. The stiffness properties of the yarns change when other parameters, such as the fiber volume content, the tension or the speed of the deformation, vary. Considering processes that combine the forming and the impregnation steps (e.g. wet molding), the resin additionally influences the friction.Presenting a newly developed experimental setup for the friction measurement between filaments is the focus of this paper.In particular, the influence of the normal force, the relative velocity, the angle between the filaments, the presence of unpolymerized matrix and its viscosity are investigated, using design of experiments..

The Way to Design a Textile with Required Critical Folding Deformation

In many textiles and fiber structures, the behavior of the material is determined by the structural arrangements of the fibers, their thickness and cross-section as well as the properties of the fibers themselves. However, this is only valid for materials, where the tension, bending and torsion deformation of yarns can be decomposed. In fibrous materials, this is the case when either bending or tension of the fibers is negligible. In textiles, it is the case when the friction between yarns is small. This theory is based on the mathematical modeling and homogenization approach and is illustrated by examples on woven structures and a spacer fabric. This paper summarizes rigorous results of asymptotic analysis and provides (1) an algorithm for computation of the shear, tension, torsion and bending properties of the textile as an orthotropic plate based on the elastic properties of yarns and the textile structure; (2) critical for its buckling force or pre-stress (thermal, swelling, etc.) computed by a simple formula from the effective textile elastic bending and tension properties; and (3) critical shear angles for the textile given in form of a simple formula in terms of the distance between yarns and their cross-section. All the theoretical results are given in terms of simple formulas and are validated in the paper by mechanical experiments.

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.

Compression resilience and impact resistance of fiber‐reinforced sandwich composites

This paper presents an experimental investigation on the compression behavior of fiber‐reinforced sandwich composites. In this study, five different types of sandwich composites were prepared with warp knitted spacer fabric as middle layer. Four different types of woven Kevlar fabric structures were used as outer layers (skin) along with one sample of woven basalt fabric. The middle layer used is 100% polyester spacer fabric. Sandwich composites were fabricated using epoxy resin by wet lay‐up method under vacuum bagging technique. Compression behavior, ball burst, and knife penetration were tested for all samples. The effect of outer layer of these composites on the mechanical performance was studied using the compression stress‐strain curves. It is known that spacers have excellent compression elasticity and cushioning. Maximum knife penetration resistance is obtained with twill weave on surface because of maximum yarn cohesion and resin impregnation. Higher amount of cohesive friction results in higher resistance against penetration of sharp objects like the knife edge. Plain and twill fabrics offer sufficient resistance again ball burst. The yarn deformation allows formation of dome shape after ball impact. Maximum impact resistance in ball burst is obtained for plain weave because of highest level of interyarn binding. The results provide new understanding of knitted spacer fabric‐based sandwich composites under compression and impact loading condition.

A Novel Simulative-Experimental Approach to Determine the Permeability of Technical Textiles

Since years, fiber reinforced polymer composite (FRPC) parts made by Liquid composite molding (LCM) make up a significant share of the composite market. In LCM dry reinforcing structure gets impregnated with a resin system. Permeability, a material parameter with key influence on all LCM processes, quantifies the conductance of technical textiles for resin flow. Today, when a numerical filling simulation is applied for process design, large experimental test programs are required for characterization of permeability, as the permeability has to be measured for all textiles processed and also the dependency e.g. on the fiber volume content has to be considered. Together with Math2Market GmbH (M2M), the IVW currently develops a novel simulative-experimental approach (SEA), using experimental tests to calibrate a simulation model for replacing a significant amount of the experimental tests through “virtual” measurements. In a first step the functionality of the simulation and the most appropriate methods for textile modelling were investigated. For this, three routes were followed: At first a micro-computer tomograph (μCT)-scan of a glass fiber non-crimp fabric was fed into GeoDict, the material simulation software developed by M2M. Second, a digital model (DM) of the textile was created by computer modelling of basic structure and subsequent virtual compaction. μCT-model and DM were then used for computational fluid flow simulation which gives the direction-dependent permeability as an output. The DM calibrated by experiments represents the SEA and results in the digital twin. Third route was the experimental permeability measurement to generate reference values. Comparing the results of all three routes allows statements about the functionality of the simulation and accuracy of modelling. The rather deficient correlation between the results of experiments and μCT-model based simulations revealed that segmentation is a remarkable source of error despite the use of recognized methods. Different modeling approaches were followed to build up the digital twin. The best results were achieved with models undergoing a virtual compaction step, which takes various imperfections such as yarn deformation and varying nesting behavior into account. With this 2.25 - 6.75% deviation from the experimental results at an average standard deviation of 21.9 - 61.2% were achieved. Hence, the digital twin shows a better correlation than the μCT-model and high potential for substitution of experiments. Even better results are expected when in a next step a local anisotropic permeability will be allocated to the yarns.