3D Composites Research Articles

Three‐dimensional (3D) woven flax fiber/polylactic acid (PLA) composites for high flexural strength

AbstractThree dimensional (3D) textiles are preferable reinforcing materials for composites with lightweight and higher mechanical properties. In this study, a 3D woven flax fiber reinforced PLA composite with better flexural and tensile properties was developed. Four hybrid yarns with varied PLA contents were prepared as warp, weft and z‐yarns to weave the 3D preform and then changed to composites through compression molding technology without additional fillers and matrixes. The composite's flexural and tensile properties were studied and an optimum value of 78.0 and 140.0 MPa respectively were found. Stress strain properties were also discussed which implies the flexural elongation is higher than those of tensile values. The microstructure was analyzed using optical microscope and SEM equipment's showed composites with higher PLA content were more brittle due to the PLA inimitable behavior. The thermal properties of the 3D composites made with different Flax/PLA combinations have closer and comparable values. One way ANOVA statistical analysis was done to show the significancy of PLA /Flax mass ratio, which has a significant effect on composite's properties. This study could bring a novel procedural approach for an advanced 3D woven composites for load bearing applications.Highlights 3D woven flax /PLA composite was developed using Flax/PLA hybrid yarns Tensile and flexural properties were studied Flexural strength increases with PLA, but, slightly lower in its strain PLA/Flax mass ratio has a significant effect on composite's properties The mechanical strengths were improved compared to the related findings

Characterization of pressure-dependent nonlinear bending behavior of yarns and its application in modeling the compression of 2D woven fabrics

This paper investigates the pressure-dependent nonlinear bending behavior of yarns, which is essential for the application of the virtual fiber modeling (VFM) method in the mechanical analyses of fabrics. An experimental method, along with a theoretical model based on classical beam theory, is presented to characterize the varying bending stiffness of yarns under different pressures. A tailored beam user element is then developed, incorporating the nonlinear bending behavior and combined with a truss element to create a physics-based virtual fiber formulation. Utilizing this formulation, the original kinematic VFM method is extended for modeling the mechanical response of 2D woven fabrics under compression. The predicted results of the proposed model closely match the reported experiment, demonstrating the significance of introducing the nonlinear bending behavior of yarns. This method can be a valuable tool for the fabric compression process and generating realistic mesoscale geometries for textile composites.

Intra-yarn fibre hybridisation effect on homogenised elastic properties and micro and meso-stress analysis of 2D woven laminae: Two-scale FE model

In this paper, the effect of intra-yarn fibre hybridisation on the homogenised elastic properties and micro- and meso-scale matrix stress fields in 2D woven composite laminae (i.e. plain, 2/2 basket, 2/2 twill and 5-harness satin) is studied with a two-scale homogenisation scheme—employing a representative volume element model at micro-scale and a repeating unit cell model at meso-scale. The study is focused on S-glass/polypropylene/epoxy woven laminae with intra-yarn fibre hybridisation. A modified random sequential expansion algorithm generates microstructure for the micro-mechanical model, and a periodic meso-structure is used to generate the weave architecture for the meso-mechanical model. Both models are verified using analytical models. It is found that intra-yarn fibre hybridisation can significantly alter the homogenised properties as well as the micro- and meso-scale matrix stress fields—depending on the degree of hybridisation (i.e. the combination of S-glass and PP fibre volume fractions). Moreover, the homogenised lamina properties are found to be less sensitive to weave architecture and yarn thickness, but more so to the degree of intra-yarn fibre hybridisation, yarn width and yarn spacing. It is shown that the lamina properties can be tailored, and the micro- and meso-stress fields can be manipulated, by intra-yarn fibre hybridisation and weave architectures.

Towards accurate prediction of the dynamic behavior and failure mechanisms of three-dimensional braided composites: A multiscale analysis scheme

In this paper, a dynamic multiscale model is proposed for three-dimensional four-directional (3D4D) braided composites, considering the effects of strain rate and shear enhanced failure mechanism. The strain rate-dependent constitutive models are established for both resin and yarns. The accuracy of the yarn model is validated by comparing the simulated stress-strain curves with the experimental results obtained from the Split Hopkinson Pressure Bar (SHPB) tests with various strain rates. The shear enhancement coefficient of the yarn is determined from the failure envelopes with a discussion of crack propagation angles. The results show that, based on the calculated microscale properties, the mesoscale model accurately predicts both the longitudinal and transverse compressive strain-stress behavior of 3D4D braided composites at different strain rates. A comparative analysis reveals that the shear-enhanced failure model achieves a better prediction compared with other counterparts, such as Hashin-Rotem and Tsai-Wu Models. The proposed dynamic multiscale scheme for 3D braided composites is an efficient and accurate tool to characterize their multiscale features and strain rate-dependent behavior.

3D printed fabrication of ultra‐structured composites of carbonyl iron powder@carbon@carbon black/polylactic acid for efficient microwave absorption

AbstractDesigning an electromagnetic wave absorber that can meet the needs of wide frequency, high efficiency, wide‐angle absorption and strong mechanical bearing capacity is still a challenge. In this paper, a core‐shell structure Carbonyl iron powder (CIP)@Carbon (C)@Carbon black (CB) composite material was prepared by coating and vacuum carbonization process. Using it as a filler, PLA as a matrix to prepare 3D printing composites. The unique structure and material distribution of CIP@C@CB gives the composite a variety of loss mechanisms that greatly improve microwave absorption capacity. Superstructure electromagnetic wave absorbers with integrating broadband microwave absorption and good mechanical bearing performance were designed and prepared by using CIP@C@CB/PLA 3D printing composites. By optimizing the parameters of this superstructure absorber, an EAB of 5.5–18 GHz is realized, and its yield limit reaches 11.5 MPa. In addition, the superstructure absorber also has excellent wide‐angle absorption capacity, with an effective absorption bandwidth (EAB) of 10GHz at 0°–40° transverse radio (TE) and 0–70° transverse magnetic wave (TM). This research offers a straightforward and effective method for crafting broadband wide‐angle absorbers that possess the added advantage of mechanical load‐bearing capacity.Highlights The core‐shell structure was prepared by coating and carbonization processes. The unique structure of CIP@C@CB enhances the interfacial polarization effect. At a thickness of 2 mm, 30% CIP@C@CB/PLA achieves a maximum EAB of 5.0 GHz. The stepped structure achieves 90% effective absorption in the 5.5–18 GHz range.

Fatigue damage evolution and residual strength analysis of 3D5D braided composites using X-ray computed tomography, acoustic emission, and digital image correlation

The accumulation of fatigue damage leads to continuous degradation of the residual strength of three-dimensional braided composites, directly determining the fatigue life. However, the inability to continuously collect residual strength and multiple damage modes pose a challenge to study the residual strength degradation mechanisms of three-dimensional braided composites. In this work, digital image correlation and acoustic emission techniques are employed to assess the strain field and damage events of the specimens during the residual strength tests. X-ray computed tomography facilitates the visualization and quantification of the fatigue damage evolution in three-dimensional braided composites. Moreover, the “two-step” damage classification method is applied to isolate the damage mechanisms. The Pearson correlation analysis is preformed between the quantitative results of three non-destructive techniques and residual strength degradation of 3D braided composites. The integration of the outcomes provides a comprehensive depiction of the residual strength degradation mechanisms.

Failure analysis of 3D woven composites under tension based on realistic model

The failure behavior of the three-dimensional (3D) woven composites under tension are evaluated via experimentation and simulation. To accurately depict the intricate geometry of the woven composites, including the fluctuation of yarn paths, variations in cross-section, and resin distribution, the image-aided digital elements modeling approach is employed. Subsequently, to further assess both the tensile performance and damage response, a realistic voxel model is established with the integration of a well-suited progressive damage model. The obtained stress–strain curves align with the experimental results, and damage progression and underlying mechanisms involved are clearly revealed. Specifically, when subjected to warp tension, severe transverse damage and fiber bundle pull-out towards the warp yarns are observed within the curved section. Similarly, under weft loading, longitudinal damage is found to occur in the weft yarns, while the warp yarns suffer from transverse damage, leading to the formation of a smooth and brittle crack. Ultimately, the findings of this study hold potential to advance the engineering applications of the 3D woven composites.

Ti─O─C Bonding at 2D Heterointerfaces of 3D Composites for Fast Sodium Ion Storage at High Mass Loading Level.

3D composite electrodes have shown extraordinary promise as high mass loading electrode materials for sodium ion batteries (SIBs). However, they usually show poor rate performance due to the sluggish Na+ kinetics at the heterointerfaces of the composites. Here, a 3D MXene-reduced holey graphene oxide (MXene-RHGO) composite electrode with Ti─O─C bonding at 2D heterointerfaces of MXene and RHGO is developed. Density functional theory (DFT) calculations reveal the built-in electric fields (BIEFs) are enhanced by the formation of bridged interfacial Ti─O─C bonding, that lead to not only faster diffusion of Na+ at the heterointerfaces but also faster adsorption and migration of Na+ on the MXene surfaces. As a result, the 3D composite electrodes show impressive properties for fast Na+ storage. Under high current density of 10mAcm-2, the 3D MXene-RHGO composite electrodes with high mass loading of 10mgcm-2 achieve a strikingly high and stable areal capacity of 3mAhcm-2, which is same as commercial LIBs and greatly exceeds that of most reported SIBs electrode materials. The work shows that rationally designed bonding at the heterointerfaces represents an effective strategy for promoting high mass loading 3D composites electrode materials forward toward practical SIBs applications.

3D laser activatable alloy-free solid/liquid biphasic conductive composites for additive manufacturable electronics

Recently, biphasic soft conductors have gained tremendous attention owing to their characteristic advantages by co-existence of solid and liquid metals. In this study, we developed the 3D printable composite that can generate alloy-free solid/liquid biphasic conductive features by 3D green-laser activation process. It comprises copper nanoparticles with localized surface plasmonic resonance in the visible wavelength regime, eutectic indium-gallium liquid metal droplets, and polyvinylpyrrolidone as a multifunctional polymeric additive. We clarify that, based on the photothermal simulation results, an instant thermal heating is triggered in the vicinity of copper nanoparticles upon green laser irradiation, which activates, comprehensively, the overall microstructural evolution reactions, including a rupture of the oxide shell surrounding the liquid metal droplets, a formation of networked copper particulate assemblies, and a combustion-free carbonization of polymeric substances. This allows us to generate double-layered biphasic conductive features in which the solid conductive compartments are in individual contact with the densified liquid metal bulks, enabling to achieve a high conductivity, excellent flexibility, self-healing capability, and solder processability without the critical problem of leakage of liquid metals.

Deep learning and integrated approach to reconstruct meshes from tomograms of 3D braided composites

The meticulous reconstruction of three-dimensional (3D) braided composite materials serves as a crucial foundation for achieving high-fidelity simulations. Nonetheless, the transition from tomographic images to a 3D mesh entails a laborious and time-intensive process. To address this, an integrated procedure based on artificial intelligence is proposed for reconstructing meshes from tomograms. The initial stage of the process involves employing artificial intelligence techniques to segment complex contours and optimize high-dimensional contours. This facilitates the input of high-quality images needed to reconstruct accurate digital twins with strong convergence. The subsequent reconstruction phase integrates various calculations, including shape interpolation, contour extraction, 3D surface reconstruction, 3D mesh reconstruction, and element data interpolation. During this process, optimization objectives are set to minimize the deviation between the digital twin's surface and the actual surface, as well as to optimize the aspect ratio of the element mesh. Upon completion of the aforementioned steps, high-quality input files suitable for finite element calculations are directly generated. Ultimately, the proposed method utilizes the reconstructed finite element model for mechanical analysis, and the results are found to be in good agreement with experimental tests. This method offers an efficient and rapid way to achieve high-quality reconstruction of complex digital twins.

Printed PZT Transducers Network for the Structural Health Monitoring of Foreign Object Damage Composite Panel

The work presented here focuses on the structural health monitoring (SHM) of a foreign object damage (FOD) composite panel equipped with an innovative printed piezoelectric transducer network. The 3D woven composite FOD panel measures approximately 800 mm x 320 mm, is curved with a cross-sectional thickness varying from approximately 2 mm to 12 mm, and a stainless-steel leading edge is bonded at one of its sides. The core idea explored here is to rely on an innovative screen-printing technology to print a full piezoelectric transducer allowing to successfully achieve SHM on such a complex composite structure. This work is being carried out within the European project MORPHO – H2020. After printing a 25 elements PZT network, a four points bending fatigue experimental campaign using the PZT network along with other sensor technologies (embedded optical fibres with FBG sensors and acoustic emission sensors) is carried out. This unique experimental campaign allows to generate data and will help to develop diagnostic and prognostic methodologies for remaining life estimation and SHM of the FOD panel. It is demonstrated here through impedance measurements that the printing process associated with the printed PZT transducers is highly repeatable thus validating its use at a larger industrial scale. Furthermore, the printed piezoelectric transducers electromechanical behaviour is characterized and they are shown to be able to detect foreign object impact and to size and localize resulting damage using Lamb waves signals collected at different locations of the network. This innovative printing technology for PZT transducers network is thus extremely promising. It is furthermore highly advantageous to use the printed transducers for SHM instead of regular ceramic ones as this technology is non-intrusive, add negligible weight, can be printed during the manufacturing process, and arrays of transducers ensure easy availability of another transducer in case of failure of one.

Wood flour and kraft lignin enable air-drying of the nanocellulose-based 3D-printed structures

The predominant technique for producing 3D-printed structures of nanocellulose involves freeze-drying despite its drawbacks in terms of energy consumption and carbon footprint. This study explores the less-energy-intensive drying approach by leveraging the valorization of forest residual streams. We utilized wood flour and Kraft lignin as fillers to facilitate room-temperature drying of the nanocellulose-based 3D printed structures. Various ink formulations, integrating cellulose nanofibers, wood flour, and lignin, were tested for direct ink writing (DIW). The formulations exhibited shear-thinning behavior and distinct yield stress with rising stress levels, ensuring the effective flow of the ink during DIW. Consequently, multilayered objects were printed with high shape fidelity and precise dimensions. Lignin and wood flour prevented structural collapse upon room-temperature drying. A reduced shrinkage was observed with the addition of lignin in freeze and room temperature drying. Moreover, the room-temperature dried samples were denser and demonstrated significantly higher resistance to applied compressive force, surpassing those reported for cellulose-based 3D composites in the existing literature. Remarkably, the trade-off effects of lignin are highlighted in terms of efficient stress-distributing and micro-scale sliding, enabling better strength. Along with wood flour, it further increases thermal stability. However, lignin hinders the hierarchical porous structure, the main ion transportation channels, reducing the double-layer capacitance of the carbonized structures. Overall, the results underscore the potential of all-biobased formulations for DIW for practical applications, highlighting their enhanced mechanical properties and structural integrity via the more sustainable drying method.

“Hexacelsian slurry development for 2D woven alumina fiber impregnation in CMC fabrication”

The rheological properties of BAS (BaAl2Si2O8) slurries are investigated in order to optimize the impregnation of an alumina preform to manufacture oxide/oxide composite materials. The fiber preform morphology has been deeply investigated, especially the fiber to fiber gap within tows and compared to the grain size of the matrix powder. The slurry viscosity is measured as a function of powder and organic additives concentration to find the best combination. The optimal combination is evaluated by different measurements including: zeta potential, sedimentation and wettability to verify the slurry behavior for the fibers infiltration. An aqueous slurry containing 20–25 vol% of BAS with 1 wt% of dispersing agent (Darvan 821-A™) improved the rheological properties for fibers infiltration. Finally, characterizations of the composite show a good infiltration in the fiber tows spaces and indicate a mean porosity of 37 vol%, including 9 vol% of macroporosity.

Tuning Electronic and Structural Properties of Lead-Free Metal Halide Perovskites: A Comparative Study of 2D Ruddlesden-Popper and 3D Compositions.

In recent decades, two-dimensional (2D) perovskites have emerged as promising semiconductors for next-generation photovoltaics, showing notable advancements in solar energy conversion. Herein, we explore the impact of alternative inorganic lattice BX-based compositions (B=Ge or Sn, X=Br or I) on the energy gap and stability. Our investigation encompasses BA2Man-1BnX3n+1 2D Ruddlesden-Popper perovskites (for n=1-5 layers) and 3D bulk (MA)BX3 systems, employing first-principles calculations with spin-orbit coupling (SOC), DFT-1/2 quasiparticle, and D3 dispersion corrections. The study unveils how atoms with smaller ionic radii induce anisotropic internal and external distortions within the inorganic and organic lattices. Introducing the spacers in the low-layer regime reduces local distortions but widens band gaps. Our calculation protocol provides deeper insights into the physics and chemistry underlying 2D perovskite materials, paving the way for optimizing environmentally friendly alternatives that can efficiently replace with sustainable materials.

Genome-wide identification of JAZ gene family members in autotetraploid cultivated alfalfa (Medicago sativa subsp. sativa) and expression analysis under salt stress

BackgroundJasmonate ZIM-domain (JAZ) proteins, which act as negative regulators in the jasmonic acid (JA) signalling pathway, have significant implications for plant development and response to abiotic stress.ResultsThrough a comprehensive genome-wide analysis, a total of 20 members of the JAZ gene family specific to alfalfa were identified in its genome. Phylogenetic analysis divided these 20 MsJAZ genes into five subgroups. Gene structure analysis, protein motif analysis, and 3D protein structure analysis revealed that alfalfa JAZ genes in the same evolutionary branch share similar exon‒intron, motif, and 3D structure compositions. Eight segmental duplication events were identified among these 20 MsJAZ genes through collinearity analysis. Among the 32 chromosomes of the autotetraploid cultivated alfalfa, there were 20 MsJAZ genes distributed on 17 chromosomes. Extensive stress-related cis-acting elements were detected in the upstream sequences of MsJAZ genes, suggesting that their response to stress has an underlying function. Furthermore, the expression levels of MsJAZ genes were examined across various tissues and under the influence of salt stress conditions, revealing tissue-specific expression and regulation by salt stress. Through RT‒qPCR experiments, it was discovered that the relative expression levels of these six MsJAZ genes increased under salt stress.ConclusionsIn summary, our study represents the first comprehensive identification and analysis of the JAZ gene family in alfalfa. These results provide important information for exploring the mechanism of JAZ genes in alfalfa salt tolerance and identifying candidate genes for improving the salt tolerance of autotetraploid cultivated alfalfa via genetic engineering in the future.

Re-engineer apparel manufacturing processes with 3D weaving technology for efficient single-step garment production

Traditional apparel assembly technology-cut and sewn process-requires labor-intensive pre- and post-production. While conventional weaving technology has made efforts to streamline the garment-making process, additional assembly processes are still required-sewing or joining after removing the woven samples from the loom. This challenge in the garment-making process discloses the need for a novel type of advanced textile technology and manufacturing techniques incorporating shaping and assembly capabilities. Exploiting three-dimensional (3D)-to-two-dimensional (2D)-to-3D methodology integrated 3D weaving technology, the 3D woven bra prototype is practically demonstrated in a significantly effective manufacturing process, shaped in one weaving cycle without additional assembly needs. The bra manufacturing process is also assessed by traditional industry loom, and the same efficient manufacturing process is also achieved. This indicates that 3D weaving technology contributes as an innovative manufacturing technology in the apparel industry to facilitate the manufacturing process significantly and eliminates further joining and sewing processes.

Experimental investigation on the damage accumulation mechanism of 3D orthogonal woven composites under repeated low-velocity impacts

This paper presents an experimental investigation into the response of carbon fiber reinforced composites with various fiber architectures to repeated low-velocity impacts. Mechanical response diagrams, including repetition numbers and damage morphologies of the composite samples, are provided. Varied energy levels (20 J, 35 J, 50 J) and impact numbers (up to 30th) are considered to induce perforated damage in the composite samples. It is found that the mechanical responses of the composite samples under repeated impact events exhibit distinct characteristics in terms of impact threshold and stiffness degradation. The 2D unidirectional (2DUD) laminated composite sample exhibits a high impact threshold during impact events but stiffness rapidly decays after an initial substantial decline. The 2D plain woven (2DPW) laminated composite sample accumulates impact damage at both high and low levels, resulting in a gradual stiffness decrease during impact events. In addition, the 3D orthogonal woven (3DOW) composite sample demonstrates a higher impact threshold with its stiffness gradually decreasing under high-level impacts. In contrast, both 2DUD and 2DPW composite samples exhibit extensive plastic deformation of the resin matrix with minimal fiber fracture, enabling efficient dissipation of impact energy. Conversely, the 3DOW composite sample primarily dissipates impact energy through fiber fracture. Additionally, it is noteworthy that while both 2DUD and 2DPW composites demonstrate enhanced robustness against repeated impacts at low-energy levels, a significant improvement in durability is observed specifically for the 3DOW composite under high-energy level impacts.

A numerical study on the effects of fabric structure on the impact resistance of 3D interlock woven fabrics

Three-dimensional (3D) woven fabrics have emerged as an effective structure for ballistic protection due to their flexibility, multi-impact resistance, and ability to form complex shapes. However, the influence of different 3D fabric architectures on ballistic performance is not fully understood. This study investigates the ballistic response of three types of 3D angle-interlock woven fabrics (3DTAWF, 3DSSWF, 3DSBWF) using numerical simulations with experimentally validated material models. Full-scale fabric models enable examining the dynamic behavior at the yarn level. Results show 3DSBWF exhibits the best ballistic performance with higher ballistic limit and energy absorption compared to 3DTAWF and 3DSSWF. Damage evolution indicates 3DSBWF and 3DSSWF have better structural integrity during penetration. The higher warp density and straighter warp path contribute to balanced warp-weft energy absorption and improved impact resistance in 3DSBWF. This study elucidates the role of 3D fabric structure on energy absorption patterns and failure morphology. The findings provide valuable insights into 3D woven fabric designs for optimizing ballistic protection performance.

Influence of the Structure of 3D Woven Fabrics on Radiation Heat Resistance and Thermophysiology Properties

The goal of this study was to investigate the influence of structural and constructional parameters of 3D fabric on two of the most significant properties of fabrics for thermal protection—resistance to radiation heat and thermophysiological properties. Today’s textile materials provide high thermal protection, but they display poor thermophysiological properties in extreme conditions. Six samples of 3D fabrics were developed using a laboratory weaving machine. The examined samples were made of identical warp, with a total of three different weft densities, and were woven in two different weaves. The conditions of the weaving process and construction were the same. EN ISO 6942:2022 and EN ISO 11092:2014 methods were used to determine the resistance of the samples to thermal radiation and thermophysiological properties. The results showed that the samples that contained folds in their structure with a larger volume of “trapped” air had better thermophysiological properties and better resistance to thermal radiation. The volume of air contained in the 3D structure was used as a thermal insulator and it did not have a negative effect on the thermophysiological properties. The described structure enabled the 3D fabric to have an optimal ratio of thermal protection and comfort, which is of crucial importance for fabrics used to make thermal protective clothing.

The Influence of MAPP and MAPE Compatibilizers on Physical and Mechanical Properties of 3D Printing Filament Made of Wood Fiber/Recycled Polypropylene

This study aims to develop 3D printing filament composites that support sustainability and waste reduction goals by utilizing wood waste and recycled polypropylene. This study evaluated the effect of Maleic Anhydride Polyethylene (MAPE) and Maleic Anhydride Polypropylene (MAPP) compatibilizers on the mechanical properties of the filament. The study found that r-WoPPc filament with MAPP and MAPE had higher tensile strength compared to r-WoPPc with significant increments of 13% and 74%, respectively, compared to v-WoPPc. The flexural strength of r-WoPPc increased by 18% and 60% after adding optimum loading MAPP and MAPE, respectively. The finding also reveals a significant enhancement in the tensile and flexural strength of the composite, proportional to the increase in MAPP percentage. In contrast, as the MAPE content increases, the tensile strength and flexural strength of the r-WoPPc experience a gradual decrease. Consequently, the addition of MAPP and MAPE improved the interfacial adhesion between wood and polypropylene, as revealed by the surface morphology of the r-WoPPc tensile fractured surface. Moreover, the reduced water absorption in r-WoPPc is attributed to the enhanced interfacial adhesion between wood fibers and the r-PP matrix, associated with improved tensile and flexural strength. The highest tensile strength of r-WoPPc with MAPP absorbs 14% water, while the lowest tensile strength absorbs 26%. Likewise, the highest tensile strength of r-WoPPc with MAPE absorbs only 0.8% water, compared to the lowest strength, which absorbs 2% water. This study demonstrated the potential for producing 3D printing filament from recycled polypropylene and wood waste, which benefits sustainability.