Properties Of Composite Structures Research Articles

Fabrication and comprehensive evaluation of Zr-based bulk metallic glass matrix composites for biomedical applications

AbstractThe aim of this study is to fabricate Zr-based bulk metallic glass matrix composites (BMG-MCs) for biomedical usage and subject them to a comprehensive and farreaching analysis with respect to their mechanical properties, biocorrosion resistance, biocompatibility, and interactions with biofilms that all may arise from their chemical compositions and unusual disordered internal structure. In this study, we fabricate Zr40Ti15Cu10Ni10Be25, Zr50Ti15Cu10Ni10Be25, and Zr40Ti15Cu10Ni5Si5Be25 alloys and confirm their glassy matrix nature through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) analyses. The mechanical properties, assessed via nanoindentation, demonstrate the high hardness, strength, and elasticity of the produced materials. Corrosion resistance is investigated in simulated body fluid, with Zr-based BMG-MCs exhibiting superior performance compared to conventional biomedical materials, including 316L stainless steel and Ti6Al4V alloy. Biocompatibility is assessed using human fetal osteoblastic cell line hFOB 1.19, revealing low levels of cytotoxicity. The study also examines the potential for biofilm formation, a critical factor in the success of biomedical implantation, where bacterial infection is a major concern. Our findings suggest, as never reported before, that Zr-based BMG-MCs, with their unique composite glassy structure and excellent physicochemical properties, are promising candidates for various biomedical applications, potentially offering improved performance over traditional metallic biomaterials.

Advances in Multiscale Modeling and Mechanical Properties Characterization of 3D‐Braided Composites

The 3D‐braided composites have been widely used in aerospace and other fields due to the excellent mechanical properties, designability, and resistance to delamination. Accurately analyzing and evaluating mechanical properties of braided composite structures is the key, which successfully designs related structural components. However, 3D‐braided composites have complex internal meso–microscopic structures, and directly establishing a solid structure model to predict mechanical behavior poses certain challenges. The multiscale research methods are a type of approach that studies the cross‐scale structural characteristics at macro–meso–microscopic scales and couples relevant scales into a whole. Its emergence provides the possibility for evaluating the overall structural performance of 3D‐braided composites. In this article, first, the multiscale analysis models of 3D‐multidirectional‐braided composites are reviewed, and then the theoretical and numerical research progress on the static and dynamic multiscale mechanical performance of regular components of 3D‐braided composites is summarized. In addition, due to the distortion and variation of geometric shapes of 3D‐braided composites on the meso–microscopic structure; therefore, also in this article, the research progress on multiscale mechanical performance characteristics of special‐shaped components is summarized. Finally, the key problems in the multiscale research of 3D‐braided composites are presented.

Characterization of PLA/LW-PLA Composite Materials Manufactured by Dual-Nozzle FDM 3D-Printing Processes.

This study investigates the properties of 3D-printed composite structures made from polylactic acid (PLA) and lightweight-polylactic acid (LW-PLA) filaments using dual-nozzle fused-deposition modeling (FDM) 3D printing. Composite structures were modeled by creating three types of cubes: (i) ST4-built with a total of four alternating layers of the two filaments in the z-axis, (ii) ST8-eight alternating layers of the two filaments, and (iii) CH4-a checkered pattern with four alternating divisions along the x, y, and z axes. Each composite structure was analyzed for printing time and weight, morphology, and compressive properties under varying nozzle temperatures and infill densities. Results indicated that higher nozzle temperatures (230 °C and 240 °C) activate foaming, particularly in ST4 and ST8 at 100% infill density. These structures were 103.5% larger on one side than the modeled dimensions and up to 9.25% lighter. The 100% infill density of ST4-Com-PLA/LW-PLA-240 improved toughness by 246.5% due to better pore compression. The ST4 and ST8 cubes exhibited decreased stiffness with increasing temperatures, while CH4 maintained consistent compressive properties across different conditions. This study confirmed that the characteristics of LW-PLA become more pronounced as the material is printed continuously, with ST4 showing the strongest effect, followed by ST8 and CH4. It highlights the importance of adjusting nozzle temperature and infill density to control foaming, density, and mechanical properties. Overall optimal conditions are 230 °C and 50% infill density, which provide a balance of strength and toughness for applications.

The synergistic mechanism of ultrasonic and heat treatment on the composite structure and mechanical properties of Nb-Si-Zr based in-situ composites

Ultrasonic assisted solidification (UST), heat treatment and alloying are all effective methods to control the microstructure of materials and improve their properties. In this paper, the Nb-16Si-20Zr-2C-xW composites were prepared using ultrasonic assisted solidification technology of high temperature melt (≥1800℃) and heat treatment. The influence mechanism of ultrasonic, the W element, and the synergistic regulation mechanism of ultrasonic and heat treatment on the material were studied. Nb-16Si-20Zr-2C-xW(UST) alloys are mainly composed of Nbss phase and γNb5Si3 phase, and their microstructures are mainly divided into strong active zone(SZ) and weak active zone(WZ). In the Nb-Si superalloy melt treated by ultrasonic wave, the area near the ultrasonic sound source is the strong active zone, while the area far away from the ultrasonic sound source is the weak active zone. The features of faceted primary phases and non-faceted primary phases in the SZ and WZ are explained by the equation of undercooling degree at different interfaces and effect of ultrasonic on component undercooling. As the W element content in the alloys (UST) increases, the content of the Nbss phase increases, the median diameter of the primary γNb5Si3 phase decreases, and the room temperature fracture toughness and compressive strength show an upward trend. When the addition amount of W element reaches 2 at%, there are more crack deflections, crack bridging and secondary cracks in the crack propagation path. Through the special arrangement of primary γNb5Si3 phase in the ultrasonic field, the energy density of ultrasonic waves in the melt is calculate to be 33.5 kW/m2. The microstructure of Nb-16Si-20Zr-2C-xW alloys(UST+HT) became more uniform and spheroidize. It is worth mentioning that there are plenty of long strip γNb5Si3 phases with different orientations in the Nb-16Si-20Zr-2C-0.1W(UST+HT) alloy and the long strip γNb5Si3 phases with the same orientation are arranged in a periodic manner. This special composite structure induces crack deflections and branching cracks when cracks propagation, so the room temperature fracture toughness of Nb-16Si-20Zr-2C-0.1 W (UST+HT) alloy reaches 15.66 MPa·m1/2.

Green synthesized CeO2 nanoparticles-based chitosan/PVA composite films: Enhanced antimicrobial activities and mechanical properties for edible berry tomato preservation.

The current study is intended to enhance unique bioactive and eco-friendly composite films following a simple solvent-casting approach by incorporating cerium oxide nanoparticles (CeO2 NPs) with a chitosan (CS)/polyvinyl alcohol (PVA) matrix. Antimicrobial activity, preservation impact, mechanisms for the edible berry tomatoes and physicochemical properties of the produced films were tested. FTIR, SEM-EDX, XRD, UV–vis spectroscopy and contact angle were used to characterize the films. Incorporated (3.0 wt%) CeO2 NPs practically developed composite film's thermal stability, structural, mechanical, bioactive, antioxidant, barrier and wettability properties. The tomatoes' look, weight loss and stiffness were better preserved after 25 days of storage at room temperature (25 ± 5 °C) when 3.0 wt% CeO2 NPs films were used instead of the original CS/PVA film. CS and CeO2 NPs have unique physiochemical and antibacterial properties. Food packaging extensively investigates the modified films as antimicrobials and preservatives to increase the shelf life of packaged foods, owing to their ability to inhibit gram-positive bacteria (Bacillus cereus and Staphylococcus aureus), gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa), and filamentous fungi (Bipolaris sorokiniana, Fusarium op., and Alternaria sp.). Our findings indicated that the CeO2/CS/PVA composite films could be used as effective wrapping materials for food preservation.

The influence of ultrafast laser processing on morphology and optical properties of Au-GaAs composite structure

The results of direct femtosecond laser structuring of GaAs wafer coated with continuous semitransparent gold (Au) film are presented. The obtained structures demonstrate a combination of different features, namely laser-induced periodic surface structures (LIPSS) on semiconductor and metal film, nanoparticles, Au islands, and fragments of exfoliated Au film. The properties of Au-GaAs samples are studied with scanning electron microscopy (SEM), Raman scattering, and photoluminescence (PL) spectroscopy. The behaviour of phonon modes and enhancement of band-edge PL of Au-GaAs composite sample are discussed. The Raman spectra of Au-GaAs sample processed at different levels of irradiation pulse energy reveal forbidden TO and allowed LO phonon modes for selected geometry of experiment, as well as the manifestation of GaAs surface oxidation and amorphization. A 12-fold increase of PL intensity for Au-GaAs sample with LIPSS compared to initial GaAs surface is observed. The detected PL enhancement is caused by an increase of absorption in GaAs due to the light field enhancement near the Au nanoislands and a decrease of nonradiative surface recombination. The blue shift of PL band is caused by the quantum size effect in GaAs nano-sized features at laser processed surface. The combination of GaAs substrate with surface micro- and nanostructures with Au nanoparticles can be useful for photovoltaic and sensorics applications.

Microstructure evolution and mechanical properties of a lamellar AlCoCrFeNi2.1 eutectic high-entropy alloy processed by high-pressure torsion

High-pressure torsion (HPT) was applied to a lamellar eutectic high-entropy alloy (EHEA) to study the effect of severe plastic deformation (SPD) on the composite structure and mechanical properties. We found that the existence of multiple phases affects defect distribution and the fragmentation process during HPT. Structural evolution shows orientation dependence with respect to the shear plane, which finally leads to a refined multiphase structure with nanograins and vortex clusters after a shear strain γ of 24. In nanograins, dislocation-mediated deformation prevails. The high density of grain boundaries, forest dislocations, and the generation of deformation twins restrict dislocation movement. As a result, an EHEA with a yield strength of 1.75 GPa, an excellent tensile strength of 2.20 GPa, and an appreciable failure strain of 5 % is realized. Our results demonstrate that the HPT deformation process of the lamellar EHEA is significantly affected by the structure. SPD on the multiphase structure is a suitable route for designing high-strength yet ductile alloys.

Synthesis and electrochemical characteristics of metal nanoparticles decorated composite anode made of domestic alloy, used in lithium ion batteries

In this work, appropriate material selection and process design enable the succesful production of high energy density electrode active material in the form of XAZ (where X, A and Z stand for electrochemically active, electrochemically inactive and carbon materials, respectively). Herein, the precipitates rich in iron and chromium are extracted selectively from a local ferrochromium alloy utilizing hydrometallurgy procedures. The precipitates are then exposed to separate calcination to get iron-rich and chromium-rich oxides seperately. In the end, a composite (XAZ) is fabricated under the mild synthesis conditions by combining these oxides with activated carbon and aluminum powder in a planetary ball mill. The composite's morphological, structural, and chemical properties are all optimized. The galvanostatic test results clearly demonstrate that the powder made of XAZ composite with embedded metal nanoparticles delivers 798 mAh g-1 after 100th cycle under a current load of 50 mA g-1 and high capacity (600 mAh g−1) over 300 cycles with an exceptional rate performance. It is anticipated that this research will create novel opportunities for producing high-value electrode active materials from accessible, low-cost raw ingredients.

Durability test study of laminated specimens for large glass fiber protective structures in seawater

The mechanical properties of glass fiber composite structures prepared by vacuum forming manufacturing process are influenced by various factors and have a certain degree of dispersion, resulting in unclear durability characteristics when applied in corrosive seawater engineering. Firstly, a variety of resin materials for underwater protective structures are tested for seawater degradation, and excellent resins that can still ensure the structural load-bearing capacity and stability after immersion are selected. Secondly, based on relevant standards and specifications, the article conducted seawater immersion aging tests at room temperature and accelerated seawater immersion aging tests at 60°C on glass fiber specimens of 430 epoxy bisphenol vinyl resin and 1967 polycyclic pentadiene resin. Finally, the degradation characteristics of strength, modulus, and impact toughness of the specimens were obtained through a series of mechanical property tests, such as bending, compression, shear and impact, under different aging time periods in room temperature and 60°C seawaters, respectively. The article summarizes the differences in the durability and mechanical properties degradation of large glass fiber protective structures with different resins during seawater immersion.

Experimental study on compression properties of composite aluminum honeycomb sandwich structures

AbstractThe mechanical properties of the carbon fiber and glass fiber composite honeycomb sandwich structure were studied through compression experiments. The influence of different aluminum honeycomb edge lengths, upper and lower panel thickness, aluminum honeycomb thickness, and loading speed on the compression failure load of carbon fiber composite laminates sandwich structure is analyzed. The influence of different aluminum honeycomb edge lengths and thicknesses on the compression failure load of glass fiber composite laminates sandwich structure was studied. The results show that the thickness of the panel has a significant effect on the failure load of the carbon fiber composite laminate sandwich structure, and the loading speed has a significant effect on the failure load of the carbon fiber composite laminate sandwich structure. The greater the loading speed, the greater the value of the failure load. The edge length and thickness of the aluminum honeycomb have a certain effect on the damage load of the carbon fiber composite laminates sandwich structure, but the influence on the mechanical properties of the glass fiber composite laminates sandwich structure is much greater.Highlights The compression performance of composite sandwich structures was experimentally studied. The influence of composite panel thickness was studied. The influence of aluminum honeycomb edge length and thickness was studied. The influence of loading speed was studied.

Mechanical properties of 3D continuous CFRP composite graded auxetic structures

A novel type of petal-like linear/linear symmetrical gradient auxetic structures with multi-stage deformation ability was designed and fabricated by using lightweight and high strength continuous carbon fiber reinforced composites to avoid the cliff-like stress drops caused by fiber fractures. The mechanical response, deformation mode and energy absorption capacity of the structures under quasi-static compression and low-speed impact loads were investigated by using finite element method in combination with experiments. The outcomes revealed that, through appropriate structural design, these auxetic structures made from fiber reinforced composites could also exhibit a stress plateau stage. Moreover, the gradient design enhanced the equivalent compression modulus of structures formed with smaller angles, while concurrently suppressing the buckling failure in structures with larger angles, thereby facilitating the predictability of structural failure. Besides, in comparison to traditional multicellular structures, the composite gradient petal-like structures exhibit superior energy absorption characteristics, thus rendering them promising candidates for applications in the construction, marine, and wind power industries.

A novel multi-scale modeling strategy based on variational asymptotic method for predicting the static and dynamic performance of composite sandwich structures

To establish a universal and convenient mathematical model for predicting static and dynamic performance of composite sandwich structures, a novel three-dimensional equivalent homogenized model (3D-EHM) is proposed based on variational asymptotic method. The multiscale mechanical analysis of composite hexagonal and re-entrant honeycomb sandwich structures is conducted by 3D-EHM, enabling reasonable transmission of mechanical information at different scales and facilitating accurate predictions of mechanical responses in sandwich structures. The comparison analysis with 3D printing experimental results and 3D finite element model results demonstrates that the 3D-EHM exhibits remarkable precision and computational efficiency in forecasting static displacement distributions and higher-order vibration modes, eliminating the need for time-consuming and expensive experiments. Moreover, the effects of the ply angle of the face sheet and core geometric parameters on the effective properties of composite hexagonal honeycomb sandwich structures are systematically investigated. In summary, 3D-EHM is an effective applied mathematical model for designing and analyzing composite sandwich structures, fully combining the systematicity of variational methods and the asymptotic convergence of asymptotic methods.

Fabrication of pesticide/LDH-LAP composite assisted by zwitterionic surfactant

Using zinc-aluminum layered double hydroxides-laponite (LDH-LAP) complex as matrix, with the assistance of zwitterionic surfactants of hexadecyl dimethyl sulfobetaine (SB) and dodecyl dimethyl carboxyl betaine (DCB), the pesticides beta-cypermethrin (BCT) and imidacloprid (IMP) were inserted into the LDH-LAP to obtain BCT/SB-LDH-LAP, BCT/DCB-LDH-LAP, BCT/SB-DCB-LDH-LAP and IMP/DCB-LDH-LAP composites, respectively. Powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), thermogravimetric/differential thermal analysis (TGA/DTA) and scanning electron microscope (SEM) were used to characterize the structural properties of composites. BCT/SB-LDH-LAP, BCT/DCB-LDH-LAP, BCT/SB-DCB-LDH-LAP and IMP/DCB-LDH-LAP had larger interlayer distances of 4.29, 4.33, 4.33 and 4.61 nm, which were bigger than those of SB-LDH-LAP (3.87 nm), DCB-LDH-LAP (3.83 nm) and LDH-LAP (1.65 nm). The FT-IR and TGA/DTA results further confirmed the existence of SB, DCB, BCT and IMP into LDH-LAP. The pesticide releases were investigated and analyzed in pH 5.0 and 6.8 buffer solutions. The release behaviors can be fitted by pseudo second-order and parabolic diffusion models. The composites based on LDH-LAP could be suggested to potential application for controlled-release of the pesticide.

Fabrication of Strontium Molybdate with Functionalized Carbon Nanotubes for Electrochemical Determination of Antipyretic Drug-Acetaminophen.

In recent years, there has been a significant interest in the advancement of electrochemical sensing platforms to detect antipyretic drugs with high sensitivity and selectivity. The electrochemical determination of acetaminophen (PCT) was studied with strontium molybdate with a functionalized carbon nanotube (SrMoO4@f-CNF) nanocomposite. The SrMoO4@f-CNF nanocomposite was produced by a facial hydrothermal followed by sonochemical treatment, resulting in a significant enhancement in the PCT determination. The sonochemical process was applied to incorporate SrMoO4 nanoparticles over f-CNF, enabling a network-like structure. Moreover, the produced SrMoO4@f-CNF composite structural, morphological, and spectroscopic properties were confirmed with XRD, TEM, and XPS characterizations. The synergistic effect between SrMoO4 and f-CNF contributes to the lowering of the charge transfer resistance (Rct=85 Ω·cm2), a redox potential of Epc=0.15 V and Epa=0.30 V (vs. Ag/AgCl), and a significant limit of detection (1.2 nM) with a wide response range of 0.01-28.48 µM towards the PCT determination. The proposed SrMoO4@f-CNF sensor was studied with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques and demonstrated remarkable electrochemical properties with a good recovery range in real-sample analysis.

Quasi-static uniaxial compression and low-velocity impact properties of composite auxetic CorTube structure

Auxetic structures are gaining great attention due to their unique contraction deformation characteristics under compression and impact. In this paper, high performance carbon fiber-reinforced composites are used to fabricate the auxetic structure consist of corrugated sheets and tubes (CorTube). The quasi-static uniaxial compression and low-velocity impact properties of composite CorTube structure are explored. The response of the composite CorTube structures under quasi-static compression loads are analyze through a combination of theoretical analysis, simulations, and experimental tests. Additionally, drop-weight impact tests are conducted using a rigid impactor with a hemispherical head to examine the effects of impact energy levels, impact locations, and corrugated sheet thickness on the impact response of CorTube structure. Enhancing corrugated sheet-tube bonding via modified cross members and reducing tube crushing during quasi-static compression are notable findings. The results also highlight the remarkable auxetic properties of the composite CorTube under low-speed impact, and the impact resistance could be enhanced by increasing the corrugated sheet thickness and stiffness. Various failure modes were observed, including cracks, pits, tube crushing, and delamination. Significantly, peak-impacted specimens exhibited greater maximum displacement with lower peak impact forces. This study offers insights into the deformation and failure modes of auxetic CorTube structures under low-velocity impact.

Mechanical and thermal characterization of elastomer modified polypropylene hybrid composites reinforced with hazelnut shell and wollastonite fillers

AbstractThe demand for sustainable and recyclable materials in industrial applications has led to a surge in interest in green composites, particularly those incorporating natural fillers derived from agro‐food industry waste. This study investigates the mechanical and thermal properties of polypropylene (PP) hybrid composites filled with hazelnut shell and wollastonite, along with the effect of styrene‐ethylene/butylene‐styrene (SEBS) and SEBS‐g‐maleic anhydride (SEBS‐g‐MA) compatibilizers. Various characterization techniques, including tensile, flexural, and impact tests, as well as differential scanning calorimetry (DSC), thermogravimetry (TGA), and scanning electron microscopy (SEM) analyses, were employed to evaluate the composites. Results demonstrate that the addition of wollastonite significantly improves mechanical properties, while hazelnut shell filler affects thermal behavior and stability. SEBS and SEBS‐g‐MA compatibilizers enhance impact resistance; however, they lead to a decrease in other mechanical properties. DSC and TGA analyses demonstrate changes in crystallization behavior and thermal stability due to filler and compatibilizer incorporation. SEM microstructure images show the distribution of SEBS and SEBS‐g‐MA within the composite structure, affecting mechanical and thermal properties. Overall, this study highlights the importance of filler selection, compatibilizer addition, and their distribution in attaining desired properties for industrial applications. Future research should focus on optimizing formulations for specific uses and assessing long‐term performance under real‐world conditions.

Crushing Performances of Kenaf Fibre Reinforce Composite Tubes

The quest for sustainable and eco-friendly materials has led to a burgeoning interest in natural fibers as reinforcements in composite materials. Kenaf fiber, derived from the Hibiscus cannabinus plant, presents a promising avenue for enhancing the mechanical and energy absorption properties of composite tubes. This study focuses on the fabrication of composite tubes using a combination of kenaf fiber and epoxy resin. The composite tubes were then subjected to compressive testing to evaluate their energy absorption performances. The fabrication process involved the impregnation of kenaf fibre with epoxy resin, followed by winding and curing to form composite tubes. Different configurations of kenaf fiber content were utilized to investigate their impact on the structural integrity and energy absorption capabilities of the tubes. Compressive testing was conducted to assess the energy absorption behaviour under axial loading conditions. The results revealed that the incorporation of kenaf fiber significantly influenced the energy absorption capabilities of the composite tubes. Higher kenaf fiber content demonstrated improved energy absorption performance, showcasing the potential of kenaf fiber as an efficient energy-absorbing reinforcement. The findings of this study offer valuable insights into the use of sustainable and renewable resources, such as kenaf fiber, in enhancing the mechanical and energy absorption properties of composite structures, thereby contributing to the development of eco-friendly and high-performance materials.

A mapping-based method capturing the mesoscopic morphological characteristics of 3D woven fabric torsion structures

Upon torsional molding, 3D woven fabrics accommodate a complex mesoscopic morphology that significantly governs the mechanical properties of composite structures. This paper is aimed to propose a macro-mesoscopic mapping method for characterizing the mesoscopic morphology of 3D woven fabric torsion structures. To this end, hyperelastic constitutive molding simulations of fabrics are performed to determine the macroscopic deformation profile within the structure in first. Then the mesoscopic details are resolved with the unit cell deformed accordingly at each digital element. A macro-mesoscopic mapping relationship is thus established by constructing a multiscale topological description function so as to tune the mesoscopic unit cells in consistency with the macroscopic manifold. Finally, the collection of mapping data is utilized for geometric reconstruction, establishing a mesoscale geometrically refined descriptive model about the torsion structure. The mesoscopic morphology of the reconstructed model is shown to agree well with experimental results. Moreover, the mapping method offers a significant time-saving strategy as the calculation time is only within a few minutes on a personal computer, in comparison with existing treatments necessitating 2-day computation on a workstation against similar tasks. The applicability of the present method to resolve other multiscale manifolds is also demonstrated.

Unsaturated polyester resin based composites: A case study of lignin valorisation

Materials from green resources boast a low carbon footprint, forming the foundation of the circular economy approach in materials science. Thus, in this study, waste poly(ethylene terephthalate) (PET) was subjected to depolymerization using propylene glycol (PG), and subsequent polycondensation with bio-based maleic anhydride (MA) produced unsaturated polyester resin (b-UPR). Bio-derived acryloyl-modified Kraft lignin (KfL-A) served as a vinyl reactive filler in the b-UPR matrix to create b-UPR/KfL-A composites. The structural characterization of KfL-A and b-UPR involved the use of FTIR and NMR techniques. The mechanical properties of the newly fabricated composites were assessed through tensile strength, Vickers microhardness, and dynamic mechanical tests. The addition of KfL-A to the rigid b-UPR matrix enhanced material flexibility, resulting in less stiff and hard materials while preserving composite toughness. For instance, incorporating 10 wt% of KfL-A in b-UPR led to a 17% reduction in hardness, a 48% decrease in tensile strength, and a 20% reduction in toughness. Positive environmental impact was achieved by incorporation of 64 wt% of renewable and recycled raw material. Analogously prepared b-UPR/KfL composites showed structural inhomogeneity and somewhat better mechanical properties. Transmission (TEM) and scanning (SEM) electron microscopies revealed a suitable relationship between mechanical and structural properties of composites in relation to the extent of KfL-A addition. The UL94V flammability rating confirmed that flame resistance increased proportionally with the KfL-A addition. Once deposited in a landfill, these composites are expected to disintegrate more easily than PET, causing less harm to the environment and contributing to sustainability in the plastics cycle.

Investigations on toughening and self‐healing performance of plain woven composites with mendable polymer stitches

AbstractThis paper investigates toughening and self‐healing properties of plain woven composite structure with poly[ethylene‐co‐methacrylic acid] (EMAA) stitches. Firstly, the cantilever beam specimens with different stitched spacing were performed to determine inter‐laminar fracture toughness. Subsequently, the finite element models of EMAA stitched cantilever beam was established to predict the toughening effects based on nonlinear spring and cohesive zone model (CZM). The force‐displacement responds of experimental and simulation results show excellent correlation. Finally, the toughening and healing mechanism of the stitched plain woven structure were explored. Compared with the original specimen, the EMAA stitched structure shows an excellent toughening ability. After heating, the damaged structure was healed through pressure deliver mechanism to restore the interlaminar fracture toughness of the composite.Highlights Thermoplastic EMAA filaments with self‐healing properties were sewn into the woven composite. The EMAA stitched woven composite structure exhibits excellent interlaminar toughening and healing properties. Finite element model combined non‐linear spring and CZM was established to predict the toughening effects. The toughening and self‐healing mechanisms of EMAA stitched plain woven structure were revealed in detail.