This study focuses on the characterization of transverse deformations, particularly through-thickness deformations, in 3D re-entrant hexagonal composite structures reinforced with fibrous materials. Given the lack of prior research on fiber-reinforced composites with this particular geometry, a measurement method based on digital image correlation (DIC) is proposed. By utilizing stereo-DIC, it becomes possible to measure the thickness variation of the sample and, consequently, its out-of-plane deformation. Experimental tensile tests were conducted on a thermoformed composite sample comprising a 4 × 4 array of re-entrant cells, with a 2 × 2 central region analyzed in detail. The sample was subjected to cyclic tensile loading, revealing a deformation homogenization phenomenon despite loading conditions designed to remain within a macroscopically linear elastic response range. A methodology for processing the experimental measurements is proposed, supported by numerical simulations to validate its accuracy. This approach aims to refine the experimental protocol and data processing techniques for samples exhibiting fewer manufacturing defects and material heterogeneities than the prototype used for method development. Furthermore, the numerical study enhances the understanding of the deformation mechanisms specific to the investigated re-entrant hexagonal composite unit cell.

This study focuses on developing a fiber-reinforced woven composite material with auxetic properties, characterized by a negative Poisson’s ratio. Auxetic materials have been shown to exhibit superior mechanical performance compared to conventional materials, offering enhanced resistance to compression, impact, and fracture. While much research has focused on architected auxetic materials, fiber-reinforced auxetic composites have received less attention. The intended application of these materials is in automotive decoupling mounts, where their dynamic and mechanical performance is evaluated. The composite material in this study is created using a 3D hollow multilayer fabric formed from a bi-component yarn, consisting of a thermoplastic core (acting as resin) and aramid multifilament (acting as reinforcement). The fabric is thermoformed to create an auxetic honeycomb structure with re-entrant hexagons. Although this geometry has been widely studied through various analytical methods, the effects of woven reinforcement-induced anisotropy on the material’s behavior need to be experimentally investigated. The paper presents the compressive mechanical response of the multicellular auxetic composite, with a focus on the deformation ratio of the overall structures.

To address environmental concerns, replacing thermoset matrices by thermoplastic ones has become a major focus in composite development. Biobased and industrially compostable polylactide, displaying good mechanical performances, is a matrix of choice to design biocomposites. This work reports the manufacturing of fully thermoplastic biocomposites combining poly(L-lactide) (PLLA) matrix and polyethylene terephthalate (PET) fabrics via thermoplastic resin transfer molding (TP-RTM) process through in-situ L-lactide polymerization catalyzed by tin (II) octoate. PLLA matrices, with L-LA conversions up to 97%, displayed weight-average molar masses over 140,000 g/mol. The resulting biocomposites exhibited an impact strength up to 99 kJ/m², flexural strength of 115.6 MPa, and modulus of 4.3 GPa. Mechanically recycled plates with 5 wt% compatibilizer reached a Charpy impact strength of 14.7 kJ/m². To date, all-thermoplastic composites have never been produced by 2 TP-RTM process. These new biocomposites represent an unprecedented way to promote the development of eco-friendly recyclable composite materials.

Composite materials, known for their exceptional mechanical performance-to-weight ratio, are increasingly used in the aerospace and defense sectors. Additionally, innovative technologies like the open rotor (with possible increased fuselage impact situations) are being integrated to mitigate aircraft fuel consumption. This evolution introduces new design challenges, particularly concerning energy absorption during impacts. Several studies indicate that auxetic materials may exhibit promising properties for impact resistance. Auxetic materials have a negative Poisson’s ratio, which causes it to expand or contract laterally under longitudinal tensile or compressive stress, respectively. In compression, this results in material densification, enhancing mechanical properties such as indentation resistance, shear modulus and energy absorption capability. Consequently, these materials emerge as viable options for enduring impact loads. Most auxetic structures are typically studied experimentally using foams or additively manufactured materials. The latter option offers advantages such as precise geometry but has drawbacks due to its layer-by-layer construction process. Technical textiles are renowned for their ability to absorb energy during impact events due to their high resilience and deformability. By manufacturing auxetic structures from technical textile-reinforced composites, both energy absorption capabilities may be synergized. The aim of this work is to design and carry out a feasibility study on such a composite reinforcement. This involves a study of the weaving pattern to obtain the auxetic geometry, the choice of yarns and control of their tension to allow the consolidation of the reinforcement into a composite material, and the verification of the correct geometry through a profilometric analysis.

This study investigates the influence of poly(ε-caprolactone) (PCL) incorporation in polylactide (PLA) on the resulting mechanical properties regarding the compatibility of melt-spun PLA/PCL immiscible polymer blends multifilaments. Different PLA/PCL blend formulations with up to 40 wt.

Needle puncture injuries present a critical occupational hazard for medical and security personnel due to the risk of bloodborne pathogen transmission. Protective gloves must therefore balance needle resistance, flexibility, and wearer comfort. This study introduces a new testing approach combining purpose-designed cylindrical fixtures engineered to replicate the geometry of human fingers with high-speed imaging for detailed analysis of perforation mechanisms. By providing a test configuration closer to real glove-use conditions, this method offers improved relevance for the design of protective multilayer textile systems. Three commercially available gloves (A, B, and C) with distinct protective architectures were evaluated: a stainless-steel/HDPE knit with a nitrile coating (A), synthetic leather with a stainless-steel weave (B), and resin plate reinforcements combined with a nylon knit (C). These were evaluated alongside newly developed multilayer gloves integrating double-weft 3D woven fabrics and shear-thickening-fluid (STF)-treated knits. By synergistically combining these established technologies into a single hybrid architecture, this study addresses the complex trade-off between high-level puncture resistance and flexibility. Commercial gloves A and B exhibited two main perforation mechanisms: initial needle-tip penetration followed by bevel-driven cutting, with maximum resistances of 5.8 N and 7.2 N, respectively. In contrast, glove C, which incorporates resin plate-like rigid elements, failed predominantly through brittle fracture and did not improve performance with a single layer of this innovative fabric (5 N). The newly developed double-weft 3D woven glove achieved the highest puncture resistance, reaching 10 N, corresponding to a 38

This chapter highlights the influence of the dynamic characteristic of yarn on the ballistic performance of fabric submitted to impact. A brief review of existing research works done on the dynamic tensile test known as the Hopkinson bar, and more recently the Split Flying Bar, is presented. A new dynamic tensile test, called the Split Flying Mass, has been proposed, ensuring improvement in the tension of yarn, accuracy of measurement, and avoiding any slippage of yarn inside the clamping jaws during high-strain velocity tests. Experimental results conducted on para-aramid multifilament yarn have confirmed the increase of stiffness, revealing the specific dynamic deformation mode of high-performance yarns used in ballistic applications.

Impact protection materials made from 3D warp interlock fabrics (3DWIFs) could be used for both ballistic and stabbing performance. Several previous studies have demonstrated the effectiveness of 3DWIFs made with para-aramid and other high-performance yarns including high modulus polyethylene fiber for ballistic and stabbing performance. However, the two dynamic events (ballistic and stabbing) imply different material behaviour of the 3DWIFS due to the different penetrator geometries and impact velocities. This study investigates the ballistic and stabbing performance and impact responses of different 3D warp interlock variants. The objective is to analyze and understand the impact response mechanisms of 3D orthogonal layer-to-layer woven fabrics made of same para-aramid fiber with same areal density but different warp yarn composition system inside the structure. Ballistics tests were conducted following the NIJ Standard-0101.06 Level IIIA, while stab resistance was evaluated using HOSBD standards. Results indicate that warp yarn configuration inside the 3DWIFs significantly influences both energy absorption, depth of penetration, and Back Face Signature (BFS). The findings provide insights into the possibility of optimizing the 3D woven fabric architectures for improved multi-layer protective performance in the future.

To address environmental concerns, replacing thermoset matrices by thermoplastic ones has become a major focus in composite development. Biobased and industrially compostable polylactide, displaying good mechanical performances, is a matrix of choice to design biocomposites. This work reports the manufacturing of fully thermoplastic biocomposites combining poly(L-lactide) (PLLA) matrix and polyethylene terephthalate (PET) fabrics via thermoplastic resin transfer molding (TP-RTM) process through in situ L-lactide polymerization catalyzed by tin (II) octoate. PLLA matrices, with L-LA conversions up to 97%, displayed weight-average molar masses over 140,000 g/mol. The resulting composites exhibited an impact strength up to 99 kJ/m2, flexural strength of 141 MPa, and modulus of 4.7 GPa. Mechanically recycled plates with 5 wt% compatibilizer reached a Charpy impact strength of 14.7 kJ/m2. To date, all-thermoplastic composites have never been produced by TP-RTM process. These new composites represent an unprecedented way to promote the development of eco-friendly recyclable composite materials.

Weaving technology has a long history and has been under development throughout civilization. The improvements in weaving technology directly influence the composites and their mechanics. Discovering the three-dimensional (3D) weaving technology was the first step to obtaining advanced weaving structures. However, the poor in-plane out-of-yarn axis tensile and in-plane shear properties of 3D warp interlock woven fabrics led to the development of a multi-axis 3D weaving method. In this advanced weaving method, the bias in-plane warp yarns can be incorporated into the 3D woven structure. Although several mechanical properties of multi-axial 3D woven fabrics and composites have been investigated, their impact properties have not yet been fully clarified. In this study, the multi-axial 3D woven composite (MA3DC) was produced and tested under main mechanical and low-velocity impact loads. Moreover, the 3D warp interlock (3DWIC) and laminated composites (LC) were produced and tested to investigate the effects of weaving technology on composite mechanics. It was concluded that the multi-axial 3D woven fabrics and their composites are one of the best solutions for impact applications among the current fabric technologies.

The integrated structure and remarkable thickness values of 3D woven fabrics provide their composites with outstanding properties such as high fracture toughness, advanced damage tolerance, high impact energy absorption capacity, etc. However, the orientation of the yarn groups through the thickness direction of the fabric degrades the in-plane mechanical properties of 3D woven fabrics/composites. This phenomenon led to the development of multi-axial 3D woven fabrics. Due to the advanced weaving methods, the bias warp yarns can be incorporated into the 3D woven structure. Previous studies have shown that the bias warp yarns significantly improve the in-plane shear properties of 3D woven fabrics/composites. On the other hand, the impact properties of multi-axial 3D woven composites have not been extensively studied. In this study, the low velocity impact properties of multiaxial 3D woven composites were investigated. First, the composites were impacted at impact energy levels of 20J, 45J and 55J. The damaged specimens were then tested at the 300J impact energy level to determine the effect of the woven fabric architecture on the impact properties and damage mechanisms of the composites. In addition, the 3D warp interlock woven and conventional laminated composites were fabricated and tested for comparative study. From the research study, it was concluded that the biased warp yarns distribute the impact energy more homogeneously to the other parts of the composite. Therefore, multiaxial 3D woven composites can absorb more impact energy than 3D warp interlock woven and laminated composites. The results obtained make multiaxial 3D woven fabrics and their composites one of the best solutions for impact applications among the current fabric technologies.

In this work, a PDMS spinning technique is developed and enables the continuous production of a filament with a circular cross-section (similar to 500 mu m diameter). The production of continuous silicone polymer filaments can be useful in the textile field to provide new properties in applications such as weaving, knitting or composite reinforcement. The method involves injecting the pre-polymer and curing agent mixture into a heated oil bath (202-215 degrees C) to simultaneously shape and cure the PDMS. The morphological and mechanical properties of the filament are studied regarding the production parameters (formulation, needle diameter, bath temperature, conveyor belt speed). The most homogeneous filament is produced at the highest temperature (215 degrees C) and conveyor belt speed (13.6 m.min(-1)). When subjected to cyclic mechanical stress, the PDMS filament produced exhibits stable mechanical behavior, making it suitable for a wide range of applications.

3D warp interlock woven fabrics (3D WIFs) are gaining popularity as composite reinforcements for their superior strength and delamination resistance, but a clear structural classification is essential to fully understand and utilize their potential in high-performance composites. This study introduces a new parameter, providing high-order definition and architectural classification. It redefines new surface warps as regular warps that are flexible in their positioning, as they connect to only one layer and eliminates the need for traditional reinforcing fabric design theory. The study also introduces the concept of wefts per column to accommodates varying layers within the structure, and an index to repeat the number of columns in the representative elementary pattern. A new parameter is introduced to define the weft insertion order, which directly influences the reinforcement behaviour. The study also considers the evolution of warps per column, allowing precise tracking of warp positions and inter-ply location changes within each column. These refinements enable the development of versatile and innovative 3D woven composite reinforcements with both regular and irregular numbers of weft yarns per column. Such features open new vistas for developing complex architectures in advanced composites, suitable for a wide range of applications including defence, aerospace, automotive, and more.

Despite numerous research investigations to understand the influences of various structural parameters, to the authors’ knowledge, no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles. Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested. Two samples, one composed of a single and the other of 4-panel layers, from each fabric type structure, were prepared, and tested against stabbing at [0°], [22.5°], and [45°] angle of incidence. A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized. The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch (HOSDB)/ P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively. A silicon compound was utilized to imprint the Back Face Signature (BFS) on the backing material after every specimen test. Each silicon print was then scanned, digitized, and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables, including Depth of Trauma (DOT), Depth of Penetration (DOP), and Length of Penetration (LOP). Besides, the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level. The results show stab angle of incidence greatly influences the stab response and performance of protective textiles. The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence, but also provide valuable information for protective textile manufacturer, armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing, testing, optimizing, and using protective textiles in various applications.

Stab-resistant textiles play a critical role in personal protection, necessitating a deeper understanding of how structural and layering factors influence their performance. The current study experimentally examines the effects of textile structure, layering, and ply orientation on the stab resistance of multi-layer textiles. Three 3D warp interlock (3DWI) structures ({f1}, {f2}, {f3}) and a 2D woven fabric ({f4}), all made of high-performance p-aramid yarns, were engineered and manufactured. Multi-layer specimens were prepared and subjected to drop-weight stabbing tests following HOSBD standards. Stabbing performance metrics, including Depth of Trauma (DoT), Depth of Penetration (DoP), and trauma deformation (Ymax, Xmax), were investigated and analyzed. Statistical analyses (Two- and One-Way ANOVA) indicated that fabric type and layer number significantly impacted DoP (P < 0.05), while ply orientation significantly affected DoP (P < 0.05) but not DoT (P > 0.05). Further detailed analysis revealed that 2D woven fabrics exhibited greater trauma deformation than 3D WIF structures. Increasing the number of layers reduced both DoP and DoT across all fabric structures, with f3 demonstrating the best performance in multi-layer configurations. Aligned ply orientations also enhanced stab resistance, underscoring the importance of alignment in dissipating impact energy.

Textile materials are used to produce open microfluidic systems without large-scale microfabrication. Sacrificial monofilament pull-out is one technique for creating closed microfluidic systems. However, removing sacrificial monofilament is manual and does not allow large-scale production. This work combines this technique with the possibilities of the large-scale output offered by weaving technologies to produce a closed microfluidic system with the minimal obstruction of the view. Three patterns (plain, twill, and satin weaves) create support reinforcements to introduce the sacrificial monofilament. They are impregnated in a polydimethylsiloxane (PDMS) matrix. The design and morphology of the microfluidic channel and the maximum extraction force are studied depending on the woven fabric parameters. All reinforcements designed have been optimized to obtain a microfluidic channel with a diameter of around 500 mu m and a length of 200 mm without fluid leakage. In addition, the woven reinforcement acted as a guide for the extraction of the sacrificial monofilament. The distribution of binding points allows the observation range to be modulated. Increasing the number of binding points results in a linear decrease in both visibility and extraction force.

The availability of the Agave Sisalana plant in Morocco and the use of this plant only in traditional medicine was the subject of the choice of the Moroccan Agave Sisalana plant in the current study for the development of multilayer woven reinforcement. The variability of natural fiber properties requires a detailed approach to the behavior of preforms developed from yarns. In this study, a multiscale analysis is established to understand the complex structure of 3D interlock warp fabrics. At the mesoscopic scale, the textile and mechanical properties of the sisal yarns are identified. The selected twisted sisal yarns are provided by the Moroccan company SONAJUTE. The linear density of twisted sisal yarns measured is around 3300 Tex with an important standard deviation. The architectures of the elementary cell of the different preforms made in the current work are designed using geometrical modeling tools (Wisetex, DB Weave). The Moroccan sisal yarns' tensile strength presented a challenge for manufacturing 3D interlock warp fabrics from these yarns. Four preforms are manufactured on a loom in the GEMTEX laboratory (Fig. 1). On a macroscopic scale, the structural properties of the 3D warp interlock fabrics are identified according to standard methods. The results revealed that the weight per unit area of the fabric influences the flexural rigidity and tenacity of the 3D warp interlock fabric.