Woven Structure Research Articles

Research on the Heating Process of CFRP Circular Tubes Based on Electromagnetic Induction Heating Method.

Based on the electromagnetic induction heating method, heating and curing of Carbon Fiber Reinforced Polymer (CFRP) have the advantages of high energy utilization and no pollution. However, in the heating process, both the material weaving structure and mold material can affect the temperature field. Therefore, in this study, an electromagnetic heating finite element analysis model for CFRP circular tubes was established based on the equivalent electromagnetic thermal characteristics of CFRP. The study investigated the temperature rise mechanism of the material weaving structure under the magnetic field, and explored in-depth the influence of molds made of 45# steel and glass fiber-reinforced plastic (FRP) on the heating process of CFRP. The CFRP circular tubes with weaving structures of 89-degree winding angle, 45-degree winding angle, and plain weave were studied. The study found that when the metal mold was heated, the CFRP structure had almost no effect on the temperature distribution. However, when the glass fiber-reinforced plastic mold was heated, the temperature field changed with the CFRP structure, and the more fiber cross points, the more uniform the temperature field. The accuracy of the finite element model was verified through experiments. The aim of this research is to provide theoretical guidance for actual industrial production.

Incorporating Variable Porosity into the Determination of Effective Permeability in Interchanging Double Cloth Woven Fabrics Using Darcy's Law.

Woven fabrics are widely used for thermal protection due to their porosity, which provides thermal insulation and breathability. This research focuses on investigating the influential parameters in the thermal protective properties of layer interchanging double cloth, including the woven structure and varying yarn fineness. The properties affecting the protective properties and comfort of multilayered woven fabrics include the fabric thickness, fabric porosity, and air permeability. Darcy's law is applicable for determining the effective air permeability of woven fabrics. By understanding and controlling fabric porosity, it becomes possible to develop thermal protective clothing that combines improved comfort, cost-efficiency, and effectiveness. This study represents a novel approach for the clarification of airflow permeability behavior in complex structures of elastic multilayer woven fabrics using Darcy's law. This innovative approach expands the understanding of permeability in fabrics beyond single-layer fabrics with vertical pores or 3D fabrics used in resin injection processes.

Enhancement of low and medium frequency sound absorption using fabrics and air gaps

Porous acoustic materials are among the most frequently employed acoustic materials. This paper evaluates the acoustic performance of porous materials concerning the addition of how the fabric layout and addition of an air gap influence sound absorption coefficient at low and medium frequencies. The acoustic measurements were performed on multilayers of woven fabrics formed from different weave structures and nonwoven fabrics using an impedance tube. The result indicates that due to the different geometrical structures of woven fabric and the layout designs of multilayer fabrics, significant improvements were observed in sound absorption performance at the frequency range from 160 Hz to 3150 Hz. The air gap with a multilayer of porous material enhanced low to medium-frequency sound absorption. Furthermore, the physical fabric properties analysis of porosity using X-ray tomography indicates that the surface of a single layer of plain fabric structures is more porous than that of sateen, rib, and twill woven fabrics. The correlation between the air permeability and sound absorption coefficient (α) results indicates an inverse relationship for multilayer porous fabrics.

Textured Polyester Fiber in Three-Dimensional (3D) Carpet Structure Application: Experimental Characterizations under Compression-Bending-Abrasion-Rubbing Loading.

In this article, textured polyester fiber was used as pile yarn in three-dimensional woven carpet structures. The properties of developed polyester carpets under various mechanical loading were studied. A statistical method was used to analyze the experimental data. Regression models were proposed to explain the relationships between carpet pile height and density. The study showed that the bending rigidity and curvature of dry and wet polyester pile fiber carpets were influenced by pile height and pile density (indirectly weft density) in that the downward concave large bending curvature was obtained from very dense carpet structures. In addition, the average dry bending rigidity of the carpet was over eight times higher than the average wet bending rigidity of the carpet. The thickness loss (%) and resilience (%) for each recovery period of various polyester carpets were proportional depending on the pile density. It was broadly decreased when the pile density was increased due to the compression load carrying capacity per polyester fiber knot, which was higher in carpets having dense knots compared to sparse knots per area. On the other hand, the polyester pile density and height largely affected the carpet mass losses (%) of all textured polyester carpets under an abrasion load. The number of strokes received after completely fractured polyester pile yarns during a rubbing test were increased when the pile heights for each pile density were increased. Findings from the study can be useful for polyester carpet designers and three-dimensional dry or impregnate polyester fiber-based preform designers in particularly complex shape molding part manufacturing.

Numerical and Experimental Analysis of Mechanical Properties in Hybrid Epoxy-Basalt Composites Partially Reinforced with Cellulosic Fillers.

The current work is focused on numerical and experimental studies of woven fabric composites modified by hybridisation with biological (cellulosic) filler materials. The mechanical performance of the composites is characterized under tensile, bending and impact loads and the effect of hybridisation is observed with respect to pure and nonhybrid composites. Numerical models are developed using computational tools to predict mechanical performance under tensile loading. The computational prediction results are compared and validated with relevant experimental results. This research is aimed at understanding the mechanical performance of basalt-epoxy composites partially reinforced with micro-/nano-sized bio-fillers from cellulose and intended for various application areas. Different weave structures, e.g., plain, twill, matt, etc., were investigated with respect to the mechanical properties of the hybrid composites. The effects of hybridizing with cellulose particles and different weave patterns of the basalt fabric are studied. In general, the use of high-strength fibres such as basalt along with cellulosic fillers representing up to 3% of the total weight improves the mechanical performance of the hybrid structures. The thermomechanical performance of the hybrid composites improved significantly by using basalt fabric as well as by addition of 3% weight of cellulosic fillers. Results reveal the advantages of hybridisation and the inclusion of natural cellulosic fillers in the hybrid composite structures. The material developed is suitable for high-end applications in components for construction that demand advanced mechanical and thermomechanical performance. Furthermore, the inclusion of biodegradable fillers fulfills the objectives of sustainable and ecological construction materials.

Preparation and electromagnetic performance of a light-weight, thin, and high-gain three-dimensional woven hollow structure microstrip antenna

With the popularity of 5 G, there is an increasing request for a light, high-performance, and stable structure for wireless communication. To solve the problems of delamination cracking and its own heavy weight of the conventional microstrip antenna, this study used ultra-high molecular weight polyethylene (UHMWPE) filament tows and purple copper filament tows as raw materials to prepare 3D woven hollow structure microstrip antenna preforms on a common loom. Using the prepared preforms for reinforcement and resin as the matrix, the VARTM process was used to prepare a 3D woven hollow structure microstrip antenna with a height of 6.8 mm, a weight of 35 g, and a bulk density of 0.7 g/cm3. The combination of the electromagnetic performance test and HFSS software simulation shows that the antenna has excellent radiation performance with a gain of 7.5 dB and a measured VSWR of 1.25. The mechanical performance test results show that it can withstand a maximum compression load of 2982 N and a maximum bending load of 364 N with no obvious delamination at the fracture. It is light, thin, and load-bearing with excellent radiation performance. There will be great potential in the unmanned field and the space field in the future.

Design and Finite Element Analysis of Artificial Braided Meniscus Model.

Currently, artificial meniscus prostheses are mostly homogenous, low strength, and difficult to mimic the distribution of internal fibers in the native meniscus. To promote the overall mechanical performance of meniscus prostheses, this paper designed a new artificial braided meniscus model and conducted finite element analysis. Firstly, we designed the spatial fiber interweaving structure of meniscus model to mimic the internal fiber distribution of the native meniscus. Secondly, we provided the detailed braiding steps and forming process principles based on the weaving structure. Thirdly, we adopted the models of the fiber-embedded matrix and multi-scale methods separately for finite element analysis to achieve the reliable elastic properties. Meanwhile, we compared the results for two models, which are basically consistent, and verified the accuracy of analysis. Finally, we conducted the comparative simulation analysis of the meniscus model and the pure matrix meniscus model based on the solved elastic constants through Abaqus, which indicated a 60% increase in strength.

THz-Based Monitoring of the Deformation of the Inner Woven Structure of Glass-Fiber Reinforced Polymers

This work exploits terahertz (THz) imaging in the real-space and the spatial-frequency domain to determine nondestructively the evolution of the main characteristics of a woven glass-fiber reinforced polymer (GFRP) laminate in three-dimensions in-situ during a tensile test. These characteristics include tow orientation and the weave period. The surface and the inner plies can be investigated with the proposed method. The results show how the tows tend to realign with the load direction. In addition, we detect a decrease in the weave period, manifesting a distortion of the surface and inner layers as the stress is increased. Contrary to conventional optical inspection, THz inspection can provide quantitative measurements in all material layers and not only on the surface. This technique could be helpful to monitor distortion and damage due to mechanical stress or defects incorporated during the manufacturing process and to validate parameters and results of draping process modeling, especially for the inner plies.

Computer geometric modeling approach with filament assembly model for 2×2 twill woven fabrics structures

Computer geometric modeling approach with filament assembly model for 2×2 twill woven fabrics structures

A modular approach for creation of any bi-axial woven structure with congruent tiles

Modularity is a fundamental and intriguing property of fabrics. Given the same set of threads, one can construct different geometries and therefore physical behavior simply by changing how those threads are linked to each other. As a result, fabrics have been studied with great interest in engineering applications. However, most engineering applications model fabrics as composite structures reinforced with a secondary material that fills the gaps between thread elements.In this work, we first show the existence of threads that are space-filling without the need for other materials. We then introduce a simple approach to construct such space-filling threads by using a single modular element that can be obtained by partitioning a cube into two yin-yang type identical pieces. These yin-yang type congruent tiles can directly be constructed by using a parametric approach. Another property of these tiles is that they are foldable, i.e., they can be constructed by folding planar materials. We show that there exist infinitely many such congruent tiles. We further demonstrate that any 2-way 2-fold woven structure can be constructed by translated and rotated versions of such congruent tiles.

A multi-scale damage model and mechanical behavior for novel light-weight C/C honeycomb sandwich structure

The high-resolution spacecraft poses an urgent need for opto-mechanical structure with ultra-high stability and light-weight. Owing to the advantages of both carbon fiber-reinforced carbon-based composites (C/C composites) and honeycomb sandwich structure, a novel C/C honeycomb sandwich structure strategy is proposed in this study. It was fabricated by using weaving fabrics and Chemical Vapor Infiltration (CVI) process, then was tested under out-of-plane compression. Taking the weave structure of honeycomb wall, anisotropy characteristics and damage mechanism of C/C composites, as well as the parameters of core size, a multi-scale damage model is established and validated to investigate mechanical behavior of the novel structure. The effects of influence factors (side length, thickness and height of core) on mechanical properties and damage mode of the novel sandwich structure are investigated. The results demonstrate that the optimal honeycomb core sizes for improving the light-weight and high load-bearing integration performance are l = 5 mm–7.5 mm and t = 0.3 mm–0.4 mm. The matrix damage occurs in the middle region of core, while fiber damage occurs at the end of core when its height reaches 15 mm. This study is helpful for design and optimization for opto-mechanical structure of high-resolution spacecraft.

Evolution of dielectric properties of Kevlar/epoxy laminated composites after hybridization by naturally woven Coco Nucifera sheaths

The present work was undertaken to examine the evolution of interfacial properties of Kevlar/epoxy laminated composites hybridized by naturally woven Coco Nucifera sheath (CNS). Hand lay-up method followed by hot pressing was performed to fabricate our laminated composites. Broadband Dielectric Spectroscopy (BDS) was adopted to investigate the effect of varying CNS fractions (0%, 25%, 50%, 75% and 100%) on the molecular dynamics and the interfacial adhesion between Kevlar/epoxy and CNS/epoxy. The surface and cross-section morphology of the samples were studied in order to analyze the weaving structures of Kevlar and CNS and the interfaces between epoxy matrix and reinforcements. Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) were carried out to control the characteristic temperatures and the interactions between the two kinds of fibers (Kevlar and CNS) and the epoxy resin. The BDS results revealed different relaxations: the conduction phenomenon, the primary [Formula: see text] -process and the interfacial polarization, called also MWS polarization, whose dielectric strength [Formula: see text] was calculated using the WinFit software. Hence, Kevlar fibers can be successfully replaced by 25% of CNS natural fibers for advanced structural applications where interfacial adhesion is prime requirement.

Influence of tetrahedral architectures on fluid transmission and heat retention behaviors of auxetic weaves

Recently auxetic textiles have captured the attention of researchers. Yet no work is reported on the development and characterization of novel tetrahedral woven auxetic structures. In this study, six two-dimensional (2D) woven auxetic structures including diamond-based vertical pointed twill (S1), vertical inverse pointed twill (S2), vertical broken pointed twill (S3), vertical pointed twill (S4), open tetrahedral (S5), and closed tetrahedral (S6) were developed. For performance analysis, thermal comfort properties including fluid transmission characteristics (air permeability, water vapor permeability index, overall moisture management capability (OMMC)), and heat retention attributes were characterized. These fabrics were also characterized by their mechanical behavior including negative Poisson’s ratio (NPR), tensile and tear strength, pilling, abrasion resistance, and stretch and growth %. S5 has longer floats, hence it became more flexible and open which resulted in higher dry fluid transmission. All specimens showed more than 85% wet fluid transmission tendencies. S6 showed the highest and S5 showed the least OMMC values. Furthermore, S2 has a higher thermal resistance because of low air permeability. The developed fabric structures showed NPR up to −0.64. A significant effect of float length has been found on the auxeticity of fabrics along the warp direction. S5 showed a higher tensile strength and stretch % in warp and weft directions. All the developed woven auxetic fabrics remained unteared in both the warp and weft directions along with viable pilling (4–5 grade) and showed improved abrasion resistance.

Scalable Core–Sheath Yarn for Boosting Solar Interfacial Desalination Through Engineering Controllable Water Supply

Tailoring water supply to achieve confined heating has proven to be an effective strategy for boosting solar interfacial evaporation rates. However, because of salt clogging during desalination, a critical point of constriction occurs when controlling the water rate for confined heating. In this study, we demonstrate a facile and scalable weaving technique for fabricating core–sheath photothermal yarns that facilitate controlled water supply for stable and efficient interfacial solar desalination. The core–sheath yarn comprises modal fibers as the core and carbon fibers as the sheaths. Because of the core–sheath design, remarkable liquid pumping can be enabled in the carbon fiber bundle of the dispersed super-hydrophilic modal fibers. Our woven fabrics absorb a high proportion (92%) of the electromagnetic radiation in the solar spectrum because of the weaving structure and the carbon fiber sheath. Under one-sun (1 kW·m−2) illumination, our woven fabric device can achieve the highest evaporation rate (of 2.12 kg·m−2·h−1 with energy conversion efficiency: 93.7%) by regulating the number of core–sheath yarns. Practical application tests demonstrate that our device can maintain high and stable desalination performance in a 5 wt% NaCl solution.

Effects of weave structure and water-repellent compositions’ formulation on the hydrophobicity property of cotton fabric

Hydrophobization is one of the most common types of final finishing of textile materials for special purposes. In recent years, in this connection, the attention of researchers has been focused on the development and production of hydrophobic materials of a new generation. Obtaining hydrophobic materials necessitates the creation of new highly effective chemical preparations, increasing the heterogeneity of the material surface. To solve this problem, in this paper, we studied the dependence of the hydrophobicity of a textile material on the surface structure of the fabric and the type of water-repellent composition based on polymers. The processing of various relief structure fabrics with water-repellent compositions was carried out using the padding method. The combined action of the relief structure of the fabric surface obtained by weaving and low surface energy imparted by water-repellent compositions ensures the hydrophobicity of the textile material. The water-repellent property stability is achieved by heat treatment of padded samples at a temperature of 150–160°C for 6–7 minutes. Studies of the processing stability showed the preservation of a sufficiently high hydrophobicity after five washes.

Bioactive impact of manuka honey and bone char incorporated into gelatin and chitosan cryogels in a rat calvarial fracture model.

Bone tissue engineered scaffolds are designed to mimic the natural environment for regeneration when typical healing is inhibited. Autografts are the current gold standard for treatment but are limited by available bone and supplementary surgical sites that broaden complications and comorbidities. Cryogels are an ideal scaffold in bone regeneration due to their mechanical integrity and marcoporous structure that elicits angiogenesis and subsequently new bone tissue formation. To aid in bioactivity and osteoinductivity, manuka honey (MH) and bone char (BC) were added to gelatin and chitosan cryogels (CG). Manuka honey has powerful antimicrobial properties to aid against graft infection, and bone char is composed of 90% hydroxyapatite, a well-studied bioactive material. These additives are natural, abundant, easy to use, and cost effective. CG cryogels incorporated with either BC or MH, and plain CG cryogels were implanted into rat calvarial fracture models for cortical bone regeneration analysis. We found indication of bioactivity with both bone char and manuka honey through the presence of woven bone structure in histology stains and micro computed tomography (microCT) data. Overall, plain CG cryogels supported greater bone regeneration capabilities than the BC or MH incorporated cryogels due to a lack of advanced organized tissue formation and collagen deposition after 8 weeks of implantation; however, future work should explore varying additive concentrations and delivery methods to further assess additive potential.

Evaluation of structural parameters to predict particle filtration and air permeability performance of woven textiles

The COVID-19 pandemic has highlighted environmental and supply issues related to single-use protective masks for both the general public and some healthcare workers. Reusable fabrics are an interesting alternative to disposable nonwovens and offer a prospect of protection in other fields such as against fine particles in urban areas. In this paper, the behavior of 22 woven fabrics regarding air permeability, simulating breathability through the material, and filtration against 3 µm diameter particles is investigated. First, basic laws are verified between the performance of a single layer of fabrics and that of a stack. A relationship is established between air permeability and filtration efficiency, allowing one to be calculated when the other is known. Second, the influence of parameters defined at various scales of the structure (fibers, yarns and fabrics) is analyzed. The most sensitive structural parameters that can be considered as predictors are then identified and used in a model allowing the calculation of air permeability. In this model two levels of porosity are taken into account: a macroscopic porosity at the scale of the woven structure and a microscopic porosity at the scale of the thread. The model proposed in this study offers a convenient method to design an effective filter from data easily measurable during manufacturing.

Combining acoustic emission and digital image correlation analysis for dynamic damage response of woven spacer structure reinforced sandwich composites

This study reveals the dynamic damage process and the bending response of woven spacer structure reinforced sandwich composites (WSRS) by combining the acoustic emission (AE) technique and the digital image correlation (DIC) method. The typical load–displacement curve of six WSRSs was divided into elastic deformation, damage developing, and rapid damage stages. According to AE, the primary failure modes of WSRS were foam failure, interface delamination and core-pile separation, and surface matrix cracking. The failure behavior of the specimens was identified. It revealed that when subjected to bending stress, the load-bearing capacity of WSRS in the weft direction was higher than in the warp direction. While the failure areas were extended, indicating that the core-pile structure played a dominant role. The stress was mainly concentrated in the core layer, increasing the failure degree and damage rate, while the strain nephogram showed superior integrity. Consequently, the weft direction of WSRS exhibited better integrity and load-bearing capacity.

Anti-interference self-powered acoustic fabric for complex acoustic environments

Traditional airborne microphones are at risk of failure due to their dependence on airborne media in complex acoustic environments (CAEs). Here, we report an anti-interference self-powered acoustic fabric (ASAF) that can shield the interfering factors in the process of sound production and propagation to serve as a precise and wearable sound receiver. The use of the soft and safe woven structure polyvinylidene fluoride (PVDF) as a vibration-sensitive layer enables the ASAF to record human speech at wide vibration frequencies (0–5000 Hz). A speech recognition system is established which can recognize 25 words related to extreme weather conditions, with more than 95.8% accuracy. This speech recognition is carried out in CAEs such as wearing masks, silent communication, windstorms, and rainstorms, with corresponding losses of accuracy less than 1.6%, 6.7%, 6.3%, and 5.8%, respectively. The ASAF is expected to facilitate outdoor rescuers, journalists, students, and other professionals working in CAEs.

Effects of woven structure and impact mode on the low-velocity impact properties and fractography of bamboo-textile-reinforced polymer composites

Bamboo-fiber-reinforced polymers have gained popularity in numerous industries because of their mechanical properties, lightweight, and ecological benefits. In this study, to determine the effects of textile structure on the impact resistance performance of bamboo-textile-reinforced polymers (BTRPs), we evaluated three impact modes: simple support beam (SSB), drop weight, and Charpy impact. We then used 3D X-ray scanning to determine the effects of the textile structure and impact modes on the microscopic fracture and crack development. The results indicated that the woven structure allowed for energy transmission in all directions during the drop weight impact test. During the SSB impact test, the large quantity of bamboo tows parallel to the major axis of the specimen increased the absorbed energy. When additional layers were added in the loading direction, the deflection of the entire specimen decreased, thus leading to lower absorbed energy. According to 3D X-ray images and quasi-static bending fracture results, similar fracture patterns appeared on dynamic and static loaded specimens. Consequently, the energy required for internal fracture and the strain energy of deflection are the two significant reasons that enable the excellent impact resistance performance of BTRPs.