Fatigue behavior of 3D textile structure resin matrix composites: A review

Structural analysis of PVC-coated fabric structures applied vertically under static air pressure

Flexible wearable sensors are widely explored for human-machine interaction and health monitoring. Electronic textiles (E-textiles) offer a promising pathway toward comfortable wearable devices by integrating sensing fibers directly into fabric structures. Among them, compared with piezoresistive and capacitive fiber sensors, piezoelectric fiber sensors require no external power supply. Compared with triboelectric fiber sensors, which are highly sensitive to humidity and temperature, piezoelectric fiber sensors provide more stable and reliable electrical signals. However, conventional piezoelectric fiber sensors still face challenges in achieving long-term wearing comfort and reliability under harsh environments. Herein, we develop a breathable, washable, and wide-temperature-tolerant based on piezoelectric perfluoroalkoxy (PFA) fibers, which can be readily integrated into E-textiles. The textile is produced via a weft knitting process that integrates coaxially structured PFA fibers with wool yarns, combining stable piezoelectric performance with wearing comfort. The fibers exhibited a charge sensitivity of (2.6 ± 0.2) pC/N at 0.2 MPa. The resulting E-textile exhibits a charge sensitivity of up to (316.6 ± 45.9) pC/N and a voltage sensitivity of (744.9 ± 73.9) mV/N. The textile maintains stable operation over a wide temperature range from -78 °C to 150 °C. Its weft-knitted structure provides breathability, while the textile also offers washability, UV resistance, and mechanical durability exceeding 10,000 stretching or bending cycles. Furthermore, the textile can effectively monitor various human motions. A smart glove constructed from five-channel PFA fibers achieved recognition accuracies above 95% for five hand gestures, demonstrating the potential offer self-powered E-textile as a wearable sensor for human-machine interaction.

ABSTRACT Lay‐up sequence and reinforcement fabric architecture play significant roles in damage formation and crack progression in hybrid composites. Here a novel hybrid composite comprising a hierarchical sandwich structure of 2D carbon fiber fabric and 3D angle‐interlock silk fabric is successfully prepared. The sandwich hybrid hierarchical structures exhibit high strength, stiffness, toughness, and energy absorption characteristics because of the strengthening effect and anti‐delamination properties of the 3D silk layer‐to‐layer angle‐interlock and through‐the‐thickness angle‐interlock woven fabrics. The 3D silk through‐the‐thickness angle‐interlock reinforcement achieves superior structural integrity and stiffness compared to that of 3D silk layer‐to‐layer angle‐interlock reinforcement. The 2D carbon/silk plain‐woven hybrid composites with 3D silk through‐the‐thickness angle‐interlock reinforcement exhibit minimum delamination volume and vertical crack distribution because of the delamination cracks deflection and strain concentration offered by the through‐thickness z‐binder yarns. Micro‐computed tomography images of the sandwich hybrid hierarchical structures show high structural integrity and fracture concentration compared to those of traditional hybrid laminates containing 2D silk woven fabric reinforcements. This study provides a promising approach for the structural optimization design of high‐strength, high‐stiffness, high‐toughness, and high‐energy‐absorption of hybrid composites.

This study investigates the impact of fiber composition and fabric structure on the liquid absorption and retention performance during pressure of weft-knitted fabrics designed for reusable incontinence products. Twelve fabric samples, made from polyester, polyamide (6.6), and viscose, were knitted in two structures—1 × 1 interlock and 1 × 1 rib—with varying stitch lengths. Key parameters such as porosity, air permeability, liquid absorption capacity (LAC), and retention capacity during pressure (RCDP) were measured and analyzed. Results showed that viscose fabrics demonstrated superior LAC (up to 312%) and RCDP due to their high hydrophilicity, fiber swelling, and porosity. Polyester and polyamide had lower LAC, with polyester performing better due to higher porosity despite its hydrophobic nature. Increasing stitch length reduced fabric density and increased porosity and air permeability, thereby enhancing LAC but decreasing RCDP. Rib structures consistently exhibited higher LAC, while interlock structures offered better RCDP due to smaller, more uniform pores. The findings highlight the importance of optimizing the porous structure by altering knitting parameters and fabric structure to develop reusable absorbent textiles that balance high absorption and retention capacity during pressure.

Shape memory alloys (SMAs) are widely used as soft actuators due to their shape memory effect, variable stiffness, and simple actuation via Joule heating. To achieve larger and more diverse deformations, SMA wires can be integrated as fibers into textile structures, enabling the fabrication of textile actuators using conventional textile manufacturing methods. These actuators provide high compliance and ergonomic conformability, making them more human-friendly than other types of soft actuators. Nevertheless, few studies have examined their modal behavior, limiting the application of SMA-based textile actuators. This study focuses on knitted SMA-based textile actuators and investigates nine morphing patterns-six plane-based and three band-based-designed with knitting codes. The actuators exhibited deformations that matched the predicted shapes. In addition, the plane-based patterns were analyzed to examine the relationship between loop transition boundaries and deformation axes in controlling bending angles. Demonstrations of knitted morphing flowers highlighted the scalability of the designs. Furthermore, quantitative evaluation of actuation forces in horizontal and vertical directions confirmed that actuator performance can be tuned through structural design.

ABSTRACT This study investigates the disconnect between upzoning policy and redevelopment feasibility, focusing on the role of minimum lot size requirements in Brisbane, Australia. A detailed analysis of zoning and lot size data reveals that most upzoned parcels fall below the threshold required for apartment or townhouse construction, implying an often-overlooked reliance on land assembly to achieve densification goals. This implicit dependence poses barriers to redevelopment, especially in established urban areas with fragmented lot patterns. To understand the origins of these constraints, the study traces the genealogy of minimum lot size regulations, dating back to 1885, highlighting the path-dependent nature of planning frameworks. This paper proposes a morphology-led approach to planning policy implementation, one that considers the physical structure, historical layering, and lot configurations of the urban fabric. By aligning densification strategies with existing morphology, planners can better identify areas where redevelopment is feasible and avoid inflating land values in areas unlikely to be developed. The findings support a shift toward more context-sensitive planning, including incremental densification and small-scale infill, as a practical alternative to large-scale redevelopment reliant on land assembly.

The relatively low theoretical capacity of conventional cathodes has become one of the key bottlenecks in developing high-energy-density lithium batteries. Iron-(III) fluoride (FeF3) cathodes are viable candidates for next-generation energy storage applications by virtue of their elevated theoretical specific capacity derived from conversion-type electrochemistry; nonetheless, their practical realization remains critically impeded by intrinsically poor electronic transport properties and substantial volumetric dilation. Herein, we employed a microfluidic assembly strategy to develop an FeF3/reduced graphene oxide (rGO) composite fabric (FGF) electrode featuring a three-dimensional network structure. In this architecture, rGO sheets are interconnected to form confined spaces that tightly encapsulate FeF3 nanoparticles into egg-roll-like structural fibers, which are further bridged to create a porous network fabric structure. Benefiting from the high conductivity, excellent mechanical strength, and moderate sheet size of rGO sheets, the resulting three-dimensional network structure not only overcomes the low conductivity of FeF3, enabling rapid electron transport, but also effectively suppresses the volume expansion and dissolution-migration of FeF3 particles during charge-discharge processes. Consequently, the as-formed FGF The electrode demonstrated superior electrochemical behavior, maintaining 98% of its initial capacity across the current density range of 0.5-5 A·g-1. Following 1000 charge-discharge cycles at 0.7 A·g-1, the active material preserved a reversible specific capacity of 72 mAh·g-1. This work not only provides an effective strategy for iron fluoride-based conversion cathodes, but also offers insights into the structural regulation of graphene frameworks for high-energy-density lithium-ion batteries, highlighting the critical importance of fluorinated graphene architectures in next-generation cathode design.

Purpose: This study examines the integration of a countershaft shedding mechanism into indigenous Ghanaian handlooms as a means of enhancing fabric mechanical performance, structural quality, and design complexity while maintaining cultural authenticity. Specifically, it evaluates how improved shedding control influences tensile behaviour, drape characteristics, pattern accuracy, and weaver experience when compared with conventional two-heddle handloom systems. Methodology/Design: A mixed-methods research design was employed, combining experimental fabric production, mechanical testing, and qualitative artisan evaluation. An indigenous four-post handloom was modified with a countershaft shedding system and used to produce woven fabrics across multiple shaft configurations (four to six shafts), including plain derivatives, twills, diamonds, and satin structures. Quantitative tensile strength tests were conducted in both vertical (warp-dominated) and horizontal (weft-dominated) directions, alongside manual and instrumental assessments of drape and structural integrity. Qualitative data were collected through surveys and expert evaluations involving master weavers from Bonwire and Agortime-Kpetoe, focusing on usability, ergonomic impact, pattern precision, and perceived fabric quality. Findings: Results demonstrate that countershaft-woven fabrics exhibit improved warp-direction tensile efficiency, enhanced stiffness control at operational strain levels, and superior drape compared to conventional handloom fabrics. Multi-shaft weave structures showed clearer motif definition, reduced yarn slippage, and more uniform interlacement. Artisans reported significantly reduced physical strain, increased weaving speed, and expanded creative freedom, enabling efficient production of complex weave structures such as straight, pointed, and diamond twills that are impractical on traditional looms. Practical and Social Implications: The countershaft shedding mechanism offers a scalable and culturally sensitive pathway for upgrading indigenous handloom technology. By improving fabric quality, reducing physical labour, and enabling higher-value textile products, the system enhances artisan productivity, market competitiveness, and occupational sustainability while preserving traditional weaving knowledge and aesthetics. Originality: This study provides one of the first integrated empirical evaluations of countershaft shedding mechanisms within indigenous handloom contexts, combining mechanical fabric analysis with practitioner-centred qualitative insights. It advances a sustainable model for handloom innovation that aligns technological enhancement with cultural continuity, positioning indigenous handwoven textiles as structurally reliable and commercially competitive in contemporary markets.

Ultrasonic welding is increasingly used to join PVC-coated polyester fabrics in membrane structures where seam reliability is critical, particularly under cold-service conditions. This study systematically investigates the effects of welding pressure (0.5,1.5 and 2.5bar), coating thickness (0.6 and 0.8mm), seam margin (6 and 12mm), and temperature (20°C and - 20°C) on the mechanical performance and failure behavior of continuously ultrasonically welded seams. A full-factorial experimental design was employed, and seam strength (N/5cm), extension at failure, work of rupture, and seam efficiency were evaluated using load-extension analysis. Increasing welding pressure from 0.5 to 2.5bar produced a 2.5-5 fold increase in seam strength and substantially enhanced energy absorption. Increasing thickness from 0.6 to 0.8mm improved seam strength. Furthermore, at a pressure of 2.5bar, increasing the seam margin from 6 to 12mm raised the seam strength from 546.0 to 1190.4. At - 20°C, seams exhibited higher strength but reduced ductility, reflecting a stiffer and more brittle response. Fractographic analysis revealed a transition from predominantly adhesive failure at low pressure to cohesive failure at 2.5bar, consistent with improved interfacial fusion. FTIR and EDS analyses confirmed that ultrasonic welding primarily induced morphological rather than major chemical changes. Regression-based predictive models were developed and validated, demonstrating reliable strength prediction under independent processing conditions. The results provide quantitative guidance for optimizing ultrasonic welding parameters to ensure durable seam performance in PVC-coated textile structures operating under both ambient and subzero environments.

Aerogel fibers are ideal candidates for thermal insulation due to their low density and high porosity. However, current aerogel fibers suffer from low mechanical strength and a lack of response to multiple stimuli. In this study, we report a strategy that uses electric field and shear flow in a dry-jet wet spinning process to make carbon nanotube (CNT)-reinforced poly(p-phenylene benzobisoxazole) (PBO) composite aerogel fibers (E-PBO/CNT). This approach resolves the usual trade-offs among strength, thermal insulation, and electrical conductivity in aerogel fibers. The aerogel fibers retain low thermal conductivity (0.039 W m-1 K-1) and high porosity (89%), while achieving high tensile strength (42.98 MPa) and high electrical conductivity (35.24 S cm-1). The aerogel fiber also exhibited thermal stability up to 650 °C, high flame retardancy (limiting oxygen index of 41%), and chemical resistance. The E-PBO/CNT aerogel fiber can be knotted or woven into textile structures, making it suitable for use in harsh environments from -196 to 300 °C, and possesses self-powered temperature-sensing capabilities.

ABSTRACT In this work, we studied the effect of calendering temperature on the morphology, structure, and mechanical properties of nonwoven fabrics produced by electrospinning from polyimide based on pyromellitic dianhydride (PMDA) and 4,4′‐oxydianiline (ODA). The formed samples were calendered at the polyamide acid stage, followed by thermal imidization. Scanning electron microscopy, Fourier transform IR spectroscopy, tensile testing, and permeability studies were used to analyze the changes. After imidization, the original nonwoven fabrics exhibited a chaotic porous structure with a predominant fiber diameter of 0.4–0.8 μm. The calendering process resulted in a significant improvement in mechanical properties: tensile strength increased by 5 times, and elastic modulus by more than 4 times compared to the original samples. It was shown that an increase in calendering temperature led to a decrease in material porosity from 71% to 38%. Thus, hot calendering is a highly efficient and technologically advanced processing method for targeted control of the properties of nonwoven polyimide materials.

The purpose of this study is to identify visual cues for distinguishing circular knit structures in on-body garment images within online environments and to empirically analyze the perceptual relationships among knit structures. Two experiments were conducted. In Experiment 1, eight experts with more than 7 years of experience were presented with 48 woven and knit garment images in random order and asked to freely describe their rationale when identifying circular knits. Analysis of the collected descriptors revealed that knit perception was systematized into three dimensions: Form, Drape, and Feel, from which 23 adjective pairs were derived. In Experiment 2, 20 experts evaluated 36 garment images composed of 12 types of circular knit structures on a 7-point scale for the 23 adjective pairs. Analysis through multidimensional scaling (MDS), hierarchical cluster analysis (HCA), and correspondence analysis (CA) revealed that knit structures were classified into four perceptual categories—flat-dense, linear-structural, patterned-ornamental, soft-cozy—and two perceptual dimensions were derived: structure cue priority versus texture impression priority (MDS: 25%, CA: 48%) and softness versus distinctness (MDS: 17%, CA: 25%). This study systematically identified the visual perceptual structure of knit structures in on-body garment images in online environments and provides foundational data for textile recognition in online fashion environments, digital merchandising, and the development of AI-based textile recognition systems.

Natural-based nonwovens featuring hollow fibers are promising for cold-protective clothing due to biodegradability and low thermal conductivity. However, their thermal behavior under varying wind intensities and orientations remains insufficiently understood. This study investigates heat-transfer mechanisms using a two-dimensional numerical model based on the porous media approach under local thermal equilibrium. To account for radiation, a radiative thermal conductivity term was integrated into the energy equation. The methodology employs a novel isolation technique: by simulating an impermeable textile zone while maintaining other transport properties, the coupled effects of conduction and radiation were separated from total heat transfer to quantify the convective contribution. The model was validated against experimental data; results show that increasing thickness is inefficient; a 2.18-fold thickness increase improved thermal resistance by only 9.9%. In contrast, reducing air permeability to levels mimicking a thin film yielded a 2.83-fold improvement by suppressing the convection that initially account for 86.2% of total heat transfer at 4 m/s. These findings indicate that controlling permeability is significantly more critical than increasing bulk for enhancing insulation. This work provides a rigorous framework for designing lightweight, high-performance thermal barriers where a balance between thermal protection and water vapor transmission is essential for cold-protective clothing.

This study investigates the performance of woven fabrics developed using modified cotton fabric, where the weft yarns consist of roving and the warp yarns are conventional spun yarns, aiming to enhance absorbency and moisture transport properties in functional absorbent textile products. Two weave structures - plain and twill - were produced with varying weft densities of 5, 7, and 9 picks/cm, using roving yarns with a yarn count of Ne 1.1 in the weft direction. A comprehensive set of standard tests was conducted, including air permeability, thermal conductivity, abrasion resistance, pilling grades, tensile strength, dimensional stability, fabric friction, fabric roughness, and moisture management performance. Two-way ANOVA was used to examine the relationships between fabric structure, pick density, and the measured performance properties, while a radar chart was employed to evaluate and compare the samples by integrating their physical, mechanical, and tactile characteristics. T9 (Twill – 9 picks/cm) ranked as the top-performing sample, followed by P9 (Plain – 9 picks/cm) and T5 (Twill – 5 picks/cm). However, based on moisture-management indicators, specifically the One-Way Transport Index (905.2%) and Overall Moisture Management Capacity (0.98), T5 showed the highest absorption efficiency, T5 optimizes moisture functionality, illustrating a trade-off between mechanical/tactile properties and moisture-management performance.

The evolution of rehabilitation aids from passive mechanical devices to intelligent systems is reshaping human motor function recovery. However, traditional orthoses often lack adaptability and comfort, highlighting the need for advanced material solutions. This review systematically explores the role of Shape Memory Textile Composites (SMTCs) in limb orthotics, bridging material science with clinical rehabilitation. We first analyze biomechanical regulation strategies for distinct limb deformities to establish design requirements. Subsequently, we discuss how SMTCs leverage advanced resin matrices and intelligent textile structures to resolve the inherent conflict between mechanical support and physiological compliance, emphasizing their environmental adaptability and active responsiveness. Furthermore, we propose a closed loop rehabilitation paradigm that integrates multi source sensing with artificial intelligence algorithms. The study concludes that fusing SMTCs with intelligent systems facilitates a transition from passive support to active neural remodeling, offering a critical pathway for next generation precision rehabilitation ecosystems.

Japanese ideophones (onomatopoeia) constitute a unique lexical system that conveys complex sensations and emotions through embodied sound symbolism. Because adults with autism spectrum disorder (ASD) show weak sensitivity to sound-symbolism, their engagement with ideophones may diverge from that of typically developing (TD) adults. We addressed this possibility in two experiments involving adults with ASD who have normal language abilities and no sensory-processing abnormalities. In Study 1, thirty-one tactile ideophones were rated on five physical and two emotional dimensions using a semantic-differential questionnaire. In Study 2, participants palpated 15 fabrics and selected all ideophones that captured each sensation. In Study 1, mean ratings, representational-similarity matrices, and response variabilities did not differ between groups, indicating that ASD adults share a semantic understanding of ideophones with TD adults. In Study 2, group-level choice distributions and the fabric representational-similarity structure based on those choices again aligned across ASD and TD groups. However, multidimensional scaling of individual choice profiles revealed pronounced dispersion in ASD. Two factors accounted for this variability: ASD participants selected fewer ideophones per fabric, and their ideophone combinations were highly idiosyncratic, whereas ideophone combinations were widely shared among TD individuals. Taken together, the results show that adults with ASD possess intact semantic representations of tactile ideophones yet adopt a more restricted and individualized strategy when translating concrete sensory experiences into linguistic expressions. This localized, less convergent usage may contribute to the qualitative communication difficulties often observed in ASD, despite intact lexical-semantic knowledge and representational similarity structures.

One important aspect influencing the mechanical properties of the composite material is thought to be the undulation of the fiber bundles in the woven fabric structure, which is employed as the reinforcing phase for the composite plate with geo-polymer resin. The unidirectional, straight, non-corrugated thread in the composite material system behaves mechanically differently from the fabric that is created during the weaving process. Furthermore, the mechanical properties of composite materials are also greatly influenced by the interaction between the fiber and matrix. Thus, it is important from a scientific and practical standpoint to assess how the parameters that define the corrugated fabric affect the elastic mechanical properties of composite plates and the reciprocal interaction between the fiber and matrix. Developing a mathematical model and computation technique to estimate the effects of reinforced plain 2D-woven fabric crimp on elastic constants of geo-composite and investigating adhesion between geo-polymer and fiber are the main goals of this paper. The simulation's findings indicate that the geo-composite panels reinforced with plain woven fabrics and very small crimped have a negligible effect on the materials' elastic constants. These outcomes also align with the experimental results.

Parachute fabrics are unique textile structures with special properties, including resistance to repeated dynamic forces, low dynamic friction, and suitable air permeability. These fabrics are commonly composed of PA 6,6 (nylon type) multifilament yarns. They are highly resistant to high-frequency cyclic deformation, lightweight, and compact. Their partial disadvantage is moisture absorption, which can limit the use and storage of parachutes in unsuitable climatic conditions. One possibility for reducing sensitivity to the presence of atmospheric moisture is the use of parachute fabrics made from PET multifilament yarns, which surpass polyamide fabrics in several properties. The aim of this work is to derive a comprehensive geometrical model of parachute fabrics, including their flattening during final calendering, and to compare the air permeability of Ortex parachute fabrics made from multifilament PA 66 and PET yarns, manufactured by Sky Paragliders, Czechia. The geometry and porosity of parachute fabrics are derived from a morphological model of an ideal honeycomb structure of multifilament and flattening of individual filaments into the shape of a Kemp cross-section. Air permeability prediction models based on the well-known linear (Darcy equation) and quadratic (Ergun equation) functions are compared. It is found that the simple linear function (Darcy equation) is suitable, especially for predicting the relationship between air pressure drop and air permeability of parachute fabrics.

Investigating the time-dependent mechanical behavior of hybrid multi-layer textile structures, designed for high-performance technical applications, is critical for ensuring their dimensional stability. This study comprehensively investigates the influence of the number of layers (2, 6, 12, and 24) on the viscoelastic creep mechanism within the seam zone of these structures. To this end, a dual-analysis methodology was employed, incorporating mathematical modeling using the four-parameter Burgers model and a complementary phenomenological analysis based on creep rate, applied to both seamed and seamless specimens. The results revealed a non-linear relationship between the number of layers and the viscoelastic properties. Mechanical performance peaked in the 12-layers structure, where the instantaneous elastic modulus (E_M) reached a maximum of 460.83 MPa, and the dynamic retardation time (τ) achieved a minimum of 2.29 min. Comparative analysis demonstrated that the seam plays a dual role: acting as a stiffness-weakening factor in thin structures (2 layers), while functioning as a mechanism that significantly retards system dynamics in thick structures (24 layers). The most significant finding was the critical role of the seam in the 12-layers structure; here, the stitched seam transformed an inherently unstable structure into an optimal structure with superior structural cohesion, acting as a stabilizing and reinforcing agent. These findings highlight the necessity of understanding the complex interaction between the seam and the multi-layer assembly for the optimal design of structures requiring high dimensional stability.