Fabric Layers Research Articles

Effect of anchorages on C-FRCM/concrete interfacial shear performance

In this study, single-lap shear tests were performed on 42 concrete specimens that were reinforced with Carbon Fabric Reinforced Cementitious Matrix (C-FRCM). The interfacial properties were enhanced through the use of fabric end-bending anchorage, a U-shaped hoop, and multiple U-shaped hoops. The bond performance of the C-FRCM/concrete interface was analyzed by examining the failure mode, ultimate stress, and interface slip of the specimens, considering four parameters: bond length of C-FRCM, number of fabric layers, fabric end-bending anchorage, and U-shaped hoop anchorage, as well as their respective mechanisms. The bond-slip constitutive parameters were calculated based on the trilinear cohesive material law and load-displacement simulation curves were obtained for each specimen through numerical simulation, which were in agreement with the test results, verifying the law's validity. Finally, the positive effect of anchorages on the constitutive parameters was analyzed.

The effect of STF-Kevlar composite materials on the impact response of fibre metal laminates

Many studies have confirmed that composite laminates made of metal and fiber reinforced composites have an excellent performance, especially when subjected to impact and fatigue loading, while maintaining a low weight-to-strength ratio. This paper presents an investigation on the impact resistance of shear thickening fluid (STF)-Kevlar composites-based fibre metal laminates (FMLs) subject to low velocity projectile impact. Firstly, the different surface treatments of aluminium alloy were carried out to identify the best bonding strength between the aluminium and composite layers, with the effect of 30V-20min anodizing treatment being identified as the best one. Secondly, impact tests were conducted on pure Kevlar fabric and STF-Kevlar composite fabric to compare their load bearing capacity and energy absorption, showing the latter with more than doubled energy absorption. Subsequently, FMLs based on STF-Kevlar and pure Kevlar fabrics were subjected to low velocity projectile impact. It is found that the impact resistance of the STF-FMLs made with one layer of STF-Kevlar composite fabric is almost equivalent to that of the FMLs made with two layers of pure Kevlar fabric. STF-Kevlar fabric, as a reinforcing material, has a significant contribution to the enhancement of the energy absorption of STF-FMLs.

Dynamic properties of natural fiber-reinforced polymer composite plates and tubes

Thirty-six flax fibre-reinforced epoxy (FFRE) plates with two, three, and four fabric layers and lengths ranging from 160 mm to 270 mm and nine FFRE tubes with a diameter of 60 mm, a length of six times the tube diameter plus an overly of 50 mm with two, three, and four fabric layers were manufactured. One-hundred-eighty impulse excitation tests were conducted on FFRE plates to determine the dynamic properties of the plates in the bending mode, and 91 impulse excitation tests were conducted on the FFRE tubes to determine the dynamic properties of the tubes in the transverse, torsional, and longitudinal directions. FFRE plates showed up to six times larger specific energy capacities compared to counterpart glass fibre-reinforced polymer plates, showing significant potential for FFRE plates to replace the use of GFRP plates where considerable damping of energy is required. The results showed that the damping ratio of the FFRE plates decreased with the increase in layers and natural frequency. For the FFRE tubes, the highest damping ratio belonged to the transverse vibration mode, followed by the torsional or longitudinal vibration modes.

A design model of multi-layer modified aramid fabrics against fragment simulating projectiles and full metal jacketed bullets

Soft body armor is required to meet threats of both bullets and explosion fragments in battlefield. However, designing body armor that can protect against these two types of projectiles considering both critical velocity and back face deformation (BFD) is often based on experience and extensive ballistic experiments. This paper proposes a quick design model for determining the layers of aramid fabrics modified by polyethylene (PE) to protect against fragment simulating projectiles (FSP) and full metal jacketed bullets (FMJ). Firstly, ballistic experiments are conducted discovering the optimal concentration of PE modification against the sphere and FSP is 10 %. Secondly, finite element model is adapted to explore the protection capabilities of modified aramid fabrics against FSP and FMJ and a linear relationship between the BFD and the critical velocity has been observed. Thirdly, an analytical model is established to uncover the reason of this relationship. Finally, a design model is proposed to configure the improved outer tactical vest (IOTV) generation III based on the derived formulae of critical velocity and BFD for different layers of modified aramid fabrics against FSP and FMJ. The model indicates that the objectives of intercepting FSP or FMJ and reducing blunt trauma are usually not simultaneously attainable. 38 layers of modified aramid fabrics are sufficient to meet the protection requirements for both FSP and FMJ, regardless of critical velocity and BFD. Besides, 498 m/s is the threshold of FMJ impact velocity to determine the priority of intercepting bullets or reducing blunt trauma. The design model can serve for the development of lightweight and effective body armor.

Exploring the release mechanism of micro/nanoplastics from different layers of masks in water: towards reduction of plastic contamination in masks.

During the COVID-19 pandemic, a substantial quantity of disposable face masks was discarded, consisting of three layers of nonwoven fabric. However, their improper disposal led to the release of microplastics (MPs) and nanoplastics (NPs) when they ended up in aquatic environments. To analyze the release kinetics and size characteristics of these masks, release experiments were performed on commercially available disposable masks over a period of 7days and micro- and nanoplastic releases were detected using fiber counting and nanoparticle tracking analysis. The study's findings revealed that there was no significant difference (p > 0.05) in the quantity of MPs released among the layers of the masks. However, the quantity of NPs released from the middle layer of the mask was 25.9 ± 1.3 × 108 to 81.3 ± 5.3 × 108 particles/piece, significantly higher than the inner and outer layers (p < 0.05). The release process of micro/nanoplastics (M/NPs) from each layer of the mask followed the Elovich equation and the power function equation, indicating that the release was divided into two stages. MPs in the range of 1-500µm and NPs in the range of 100-300nm dominated the release from each layer of the mask, accounting for an average of 93.81% and 67.52%, respectively. Based on these findings, recommendations are proposed to reduce the release of M/NPs from masks during subsequent use.

Inactivation of microorganisms on fabrics using plasma-activated nebulized mist driven by different plasma gases

The disinfection of fabrics is crucial in preventing the spread of infectious diseases caused by pathogenic microorganisms to maintain public health. A previous study proved that plasma-activated nebulized mist (PANM) could effectively inactivate microorganisms both in aerosol and attached to the surface. In this study, the PANM driven by different plasma gases were employed to inactivate microorganisms on diverse fabrics. The PANM could efficiently inactivate a variety of microorganisms, including bacteria, fungi, and viruses, contaminating different fabrics, and even across covering layers of different fabrics. The mites residing on the cotton fabrics both uncovered and covered with various types of fabrics were also effectively inactivated by the PANM. After 30 times repeated treatments of the PANM, notable changes were observed in the color of several fabrics while the structural integrity and mechanical strength of the fabrics were unaffected and maintained similarly to the untreated fabrics with slight changes in elemental composition. Additionally, only trace amounts of nitrate remained in the fabrics after the PANM treatment. Therefore, the PANM treatment supplied an efficient, broad-spectrum, and environmentally friendly strategy for industrial and household disinfection of fabrics.

Comparison of mechanical and comfort properties of natural fiber-based spacer fabrics for shoe insole

The objective of this study is to develop an improved shoe insole that enhances heat and moisture transmission (thermo-physiological comfort) qualities, as well as its mechanical characteristics, through the utilization of weft knitting spacer fabric. Two samples were prepared. One sample was comprised of Tri-Blend knitted fabric layers, while the other sample was made using cotton knitted fabrics in both layers. These layers, in both samples, were connected by spacer yarns of monofilament nylon. Tri-blend fabric was made from Bamboo (80%), flax (15%), and polypropylene (5%). Monofilament nylon was used in spacer layer. Thermo-physiological comfort testing i.e., air permeability, moisture management and thermal resistance test were performed for all the samples. The investigation also established the correlation between the mechanical properties, such as puncture resistance and tactile comfort, of footwear materials and their interaction with the human body. The prepared samples of shoe insole were also compared with the commercially available insoles made from synthetic materials. The outcome of the study suggests that the natural fiber spacer fabric can be used as an alternative to rubber. In conclusion, the results of this study offer valuable insights for product developers seeking sustainable alternatives that can meet consumer demands for both wearability and comfort.

The Tensile Behavior of Hybrid Bonded Bolted Composite Joints: 3D-Digital Image Correlation versus Finite Element Analysis.

This study examines the behavior of hybrid bolted/bonded (HBB) joints loaded in tensile shear comprising plain weave carbon/epoxy laminates in quasi-isotropic (QI) and cross-ply (CP) layups. It proposes a combined approach of 3D digital image correlation and finite element analysis (FEA) to assess their behavior. To apply the FEA simulation accurately, a single layer of plain fabric was replaced with [0/90]s lamination. Experimental standard open-hole tension test results, as well as only bolted (OB) and HBB, along with FEA predictions, confirmed the accuracy of the substitution method. The FEA, calibrated by experimental results, provides insight into the distinctive characteristics of HBB joints in comparison with bonded and bolted joints. Critical considerations include material properties, damage modeling, adhesive characteristics, and mass scaling. The FEA results underscored the pivotal role of adhesives in HBB joints, rendering them akin solely to bonded configurations. HBB joints retain their geometry better than OB joints with considerably less out-of-plane displacement, following a sinusoidal trend. Moreover, the overall behavior of the two layups demonstrates that CP benefits from having higher strength than QI, especially at the critical hole located closer to the grip side.

Analyzing the Tensile Strength of Carbon Fiber-Reinforced Epoxy Composites Using LabVIEW Virtual Instrument

Carbon fiber-reinforced polymer composites are widely used materials in the aircraft industry, automotive sector, marine applications, civil engineering, and daily consumer goods, due to their superior mechanical properties at a relatively low density compared to metallic materials. The studied composites are composed of an epoxy resin matrix in which three layers of carbon fiber fabric are embedded, oriented at 0 and 90 degrees. Carbon fiber-reinforced polymer composites were manufactured using the Vacuum Assisted Resin Transfer Molding technique. The tensile failure mechanism in carbon fiber-reinforced polymer composites is an extremely complex phenomenon influenced by numerous factors. This study aims to evaluate the mechanical behavior of carbon fiber-reinforced composites through tensile testing and to compare experimentally obtained results with those calculated using the mixture rule. Additionally, the behavior of the materials under tensile stress was analyzed using the digital image correlation method. Estimating mechanical properties based on the mixture rule is a common practice in the design phase of polymer composites. This study s novelty and originality lie in its anticipation of the tensile strength and modulus of elasticity of the studied composites. This anticipation was achieved using a virtual instrument developed in the LabVIEW graphical programming environment. The experimentally obtained results for the tensile characteristics of the studied materials are suitable for this type of composite. These results were compared with estimates derived from the mixture rule, and the absolute error was determined.

Seismic and dynamic response characteristics of flax fiber-reinforced epoxy pipes

Dynamic and seismic response characteristics of free-spanning above-ground flax fibre-reinforced epoxy (FFRE) pipes with various diameters of 38, 60, 100, 160, and 205 mm and different fabric layers of 2, 3, and 4 (thickness of 3.4 mm–6.65 mm), and a free span of 3870 mm were investigated experimentally and numerically. The FFRE pipes were subjected to harmonic ground motions with peak ground acceleration of 0.1g, 0.2g, and 0.3g, vibration frequency of 2, 4, and 6 HZ, and a duration of 40 s, and a record from the 2011 Christchurch earthquake when the pipe was empty, half-filled or completely-filled with water to establish the effect of peak ground acceleration, vibration frequency, pipe water content, diameter and thickness on pipe displacement, acceleration, strain, and internal pressure. FFRE pipes underwent larger displacements and strains and higher transverse accelerations when the pipe was completely-filled, while the pipe underwent higher vertical acceleration and higher internal pressure when the pipe was half-filled. The pipe strain increased by up to 719% by increasing the peak ground acceleration from 0.1g to 0.3g, up to 452% by increasing the vibration frequency from 2 to 6 Hz, and up to 1358% by increasing the pipe water content from empty to completely-filled. FFRE pipes remained below their material ultimate limits, and no service or structural failure in the form of seepage or excessive deformation was detected in the pipe body, indicating great potential for using FFRE pipes as an alternative option to conventional pipes at seismic zones.

Digital Copyright Management Strategy of Digital Library Based on Blockchain Technology

Using blockchain technology to handle the entire chain of digital copyrights in digital libraries not only helps to improve the economy, validity, and fairness of the libraries’ digital resource offerings, but it also increases the revenue of digital copyright subjects in a sustainable manner. In this work, a decentralized, secure, and traceable digital copyright transaction system is designed and implemented using blockchain technology. The system serves creators, administrators, and subscribers through its user layer, business model layer, and Fabric network layer. To guarantee the accuracy and integrity of transaction data, smart contracts are used for the registration of digital works, transaction supervision, and smart contract execution. Fabric Composer is used in the development of the system and offers good scalability. The system still has issues with privacy protection, increasing performance, and complying with laws and regulations. It is anticipated that the digital copyright transaction system will advance in the area of digital copyright protection as blockchain technology develops.

Effect of Textile Layers and Hydroxypropyl Methylcellulose on Flexural Behavior of TRLC Thin Plates

To examine the flexural toughness characteristics of textile-reinforced lightweight aggregate concrete (TRLC), a four-point bending test was conducted to assess the impact of varying numbers of textile layers and the inclusion of hydroxypropyl methylcellulose on the ultimate load-bearing capacity and deformation capacity of TRLC thin plates. Six groups of specimens were prepared for the experiment, and the bending capacity of the thin plates in each group was evaluated. The flexural toughness index was utilized to quantify the bending performance of TRLC thin plates. The findings revealed that increasing the number of textile layers improved the initial cracking load, initial cracking deflection, ultimate load, ductility, and flexural toughness of the thin plates. For the specimens without HPMC, the initial cracking load was increased by up to 36.1%, the ultimate load by up to 40.9%, and the flexural toughness index by up to 292% as the number of textile layers was increased. For specimens doped with HPMC, the initial cracking load was increased by up to 61.7%, the ultimate load by up to 246.7%, and the flexural toughness index by up to 65%. The TRLC thin plate containing hydroxypropyl methylcellulose exhibited a reduced initial cracking load yet displayed a stronger matrix consistency and good flexural toughness. Moreover, the enhancement in the ultimate load of TRLC thin plates with hydroxypropyl methylcellulose was more pronounced with an increased number of textile layers, resulting in a significantly higher number of cracks compared to TRLC without hydroxypropyl methylcellulose and an 11.40-fold increase in the flexural toughness index.

Effects of textile type on the flexural properties of prefabricated hollow-core slabs strengthened with PVA fibers-improved TRM

In this study, the utilization of textile-reinforced mortar (TRM) in the strengthening and rehabilitation field is investigated. To regulate crack width, polyvinyl alcohol (PVA) fibers were incorporated into the TRM matrix. Nine prefabricated hollow-core slabs strengthened with TRM, along with one reference slab, were subjected to static loading using a 4-point bending apparatus. The experimental variables consisted of the type of textile (glass, basalt, and carbon) and the number of textile layers (one, two, and three layers). The experimental findings demonstrated that the inclusion of PVA fibers improved the TRM by effectively controlling crack width and increasing energy absorption capacity. Among the textile types, carbon TRM-strengthened slabs exhibited the highest flexural capacity. This capacity increased by 74%, 119%, and 132% for slabs strengthened with one, two, and three layers of textile, respectively. Glass TRM-strengthened slabs demonstrated superior deformability, with an increase rate ranging from 202% to 331%. Finally, to predict the flexural capacity and deflection of the tested slabs, a theoretical analysis was conducted and validated by comparing the theoretical predictions to the actual test results for accuracy and reliability.

Compressive Strength and Elastic Modulus of a 3D Woven Glass/Polyester Fire-Retardant Sandwich Composite

A 3D woven sandwich composite structure has been widely used in various fields due to its advantages in terms of its strength-to-weight ratio. The adoption of lightweight materials in the railway industry for train carriages is aligned with United Nations Sustainable Development Goal 11, as this fosters the development of sustainable transportation by reducing carriage weight, enhancing fuel efficiency, minimizing component wear, and mitigating air pollution. This study explores the effect of the addition of aluminum trioxide (ATH) filler on the core structure, density, compressive strength, elastic modulus, and the number of added layers of 3D woven core fabric with 2D woven face sheets. Sandwich composites were produced with varying ATH loads of 30%, 40%, and 50%. We also varied the number of 3D woven core fabric layers in the composite sandwich (one, two, three, and four layers) and the 2D preform (one on the upper side, two on the upper side, and one on the upper + two on the lower sides) used as a face sheet thickener. The results showed that the addition of ATH filler increased the composite density. The addition of up to 40% ATH improved the strength and elastic modulus of the composite, while excessive loading led to a decrease in both properties. Variation of the 3D and 2D preform layers also improved the compressive strength and elastic modulus. We conclude that 3D woven sandwich composites incorporating 40% ATH, multilayered 3D woven core fabric, and 2D woven fabric face sheet thickener represent promising materials for use in the railway industry.

Experimental Study on the Mechanical Properties of Nylon Fabric-Reinforced Elastomeric Isolators (N-FREIs)

In recent decades, carbon fiber, glass fiber, polyester and Kevlar fiber have been utilized to replace the steel shims in conventional steel-reinforced elastomeric isolators (SREIs). This study chose nylon fabrics owing to their extreme low cost, low elastic modulus and good adhesion to rubber, and nine nylon fabric-reinforced elastomeric isolators (N-FREIs) were manufactured with different design parameters. Compression and compression shear tests were, respectively, conducted to investigate the mechanical properties together with their influential factors of the N-FREIs. Results show that the vertical load-carrying capacity of the isolator is high enough to sustain a compressive stress of 10[Formula: see text]MPa without visible damage. The compressive stiffness of N-FREI is much smaller than that of SREI, and the vertical damping ratio under cyclic compression reaches up to 7%. In the compression shear tests, the shear stiffness of the isolator first decreases and then increases as the shear strain increases within 300%, and the equivalent damping ratio varies between 9% and 14% for different sizes of the isolator. Additionally, due to the flexibility and extensibility of the low modulus nylon fabric, both vertical and horizontal stiffness decrease a bit with an increase in the number of fabric layers. Finally, a formula for calculating the horizontal stiffness of N-FREI is proposed, it provides a comprehensive mathematical model to predict the behavior of the N-FREI under horizontal shear conditions.

Experimental study and theoretical analysis on tensile properties of concrete reinforced with different polymer-impregnated basalt textiles

Textile-reinforced concrete (TRC) has become a new material for strengthening and constructing structures. The mechanical properties of TRC are significantly influenced by the polymer impregnation of textile. However, the influencing mechanisms of different polymers on the mechanical properties of TRC remain unclear. In this study, the effects of polymer impregnations on tensile behavior of basalt textile reinforced concrete (BTRC) were investigated. The results showed that the epoxy resin-impregnated basalt textile outperformed other polymer-impregnated textiles in improving the tensile properties of concrete, exhibiting an ultimate stress 48%–110% higher than other samples. Increasing the textile layers number from 1 to 3 improved the ultimate stress and energy consumption, with the most notable improvements observed at 146% and 173%, respectively, for samples reinforced with epoxy resin-impregnated textiles. However, the increased textile layers reduced the ultimate strain and fiber strength utilization efficiency due to the inconsistent stress transfer among multi-layer textiles. Only epoxy resin-impregnated textiles reinforced samples exhibited a complete three-stage variation in the tensile stress-strain curve, where the stress fluctuations in the post-cracking stage were attributed to the multiple concrete cracks. In contrast, other polymer-impregnated textile-reinforced concrete samples experienced stress fluctuations in post-cracking stage primarily due to the textile slippage, inconsistent textile fractures, and propagation of initial crack. Furthermore, the epoxy resin-impregnated textiles' superior tensile strength and excellent bond with concrete contributed to reduced stress fluctuation range and smaller stress drop after initial cracking. Finally, an optimized tensile model with high accuracy was proposed to describe the tensile response of polymer-impregnated basalt textile reinforced concrete.

Autoclaved aerated concrete masonry wallettes strengthened using TRC overlay under out-of-plane load

The objective of this study is to assess the out-of-plane flexural responses of autoclaved aerated concrete (AAC) masonry wallettes externally strengthened with textile reinforced concrete (TRC) overlay. This method can be applied as a retrofitting technique for existing AAC masonry walls or as a constructive technique for new constructions. Sixteen AAC masonry specimens (shear span ratio = 5) were subjected to monotonic four-point bending loads. The design variables were the textile types and number of textile layers (reinforcement ratio). The load–deflection responses and corresponding flexural performances of specimens were assessed to quantify the influences of different test parameters. Results showed that the higher tensile strength of TRC would change the failure mode of AAC masonry wallettes from bending to shear. Finally, according to the different failure pattern observed in the tests, flexural and shear models available in the literatures were examined to assess their applicability to predict the load-carrying capacity of AAC masonry wallettes strengthened with TRC.

The Structural Performance Of Short Circular Concrete Columns Made With Reactive Powder Concrete And Externally Reinforced With Textile Fabric

In the current laboratory investigation, the behavior of hollow circular concrete columns exposed to vertical compressive force is examined. The columns are externally strengthened with Glass Fibre Reinforced Polymer bars and textile fabric (one layer and two layers). The longitudinal reinforcement cast using concrete Reactive Powder Concrete has an outer diameter of (250 mm), a bore diameter of (100 mm), and a length of (1000 mm). The number of textile layers (one or two layers) is one of the main variables used in this experiment study. According to the experimental findings, the hollow circular concrete columns raised the tested concrete columns' bearing capacities by roughly (9.93%) and (17.8%), respectively, after the specimens were allowed to cure for 28 days. This improvement was made for strengthening columns that were subjected to compressive loads and had one or two layers of textile fabric.

Comparative clinical trials of tourniquets and elastic bandages for emergency hemostasis at the pre-hospital stage

Comparative clinical trials of tourniquets and elastic bandages for emergency hemostasis at the pre-hospital stage

Investigation of Flexural Bearing Behavior of Corroded RC Strengthened with U-Type TRC.

In this study, the flexural bearing behavior of corroded reinforced concrete (RC) beams reinforced with U-type Textile Reinforced Concrete (TRC) was investigated using a four-point bending loading method. Nine test beams were produced: one original beam, three RC beams with corrosion alone, and five corroded beams strengthened with U-type TRC. The analysis focuses on assessing the impacts of the steel corrosion degree and the number of textile layers on various aspects of the bending behavior, such as failure modes, bearing capacity, and load displacement curves, in U-type TRC-strengthened corroded beams. The experimental results revealed three distinct failure modes in the U-type TRC-strengthened corroded beams. TRC effectively enhanced the bearing capacity. With sufficient textile layers, it can be restored to the level of the original RC beams. Moreover, in the cases of severe corrosion in RC beams, the bearing capacity increased more significantly. The TRC also enhanced the ductility. Finally, a calculation equation for the ultimate bearing capacity of U-type TRC-strengthened corroded beams was presented and validated, demonstrating consistent alignment with the experimental data.