Journal of Composites Science

21 pages, 19005 KB

Open AccessArticle

Experimental Evaluation of Induction- and Conduction-Welded Thermoplastic Composite Single-Lap Shear Joints

by Arne Schiller and Chiara Bisagni

J. Compos. Sci. 2026, 10(5), 241; https://doi.org/10.3390/jcs10050241 - 29 Apr 2026

Single-lap shear joints made from fabric T300/polyphenylene sulfide (T300/PPS) and unidirectional T700/low-melt polyaryletherketone (T700/LM-PAEK) laminates are joined via induction and conduction welding at different processing temperatures. The joints are tested experimentally to investigate the influence of the processing temperature on the damage evolution [...] Read more.

Single-lap shear joints made from fabric T300/polyphenylene sulfide (T300/PPS) and unidirectional T700/low-melt polyaryletherketone (T700/LM-PAEK) laminates are joined via induction and conduction welding at different processing temperatures. The joints are tested experimentally to investigate the influence of the processing temperature on the damage evolution in the specimens which is tracked using digital image correlation. Cracks grow rapidly in the unwelded parts of the joint interface but assume a stable steady-state propagation rate when reaching the fully welded overlap region. It is found that higher welding temperatures lead to longer weld lengths, which improve the strength and stiffness of the specimens and delay damage initiation. An accelerated crack growth rate indicates that the structure is close to its ultimate load after which the joint fails abruptly as the crack growth becomes unstable. Induction welding temperatures at the upper end of the recommended processing window (330 C for T300/PPS and 385 C for T700/LM-PAEK) result in the joints with the highest load-carrying capacity and slowest crack propagation, but also the least damage tolerance. Full article

(This article belongs to the Special Issue Functional Composites: Fabrication, Properties and Applications)

24 pages, 11033 KB

Open AccessArticle

A Study of the Effect of Activated Waste from Ferroalloy Production on the Performance Properties of Concrete for Reinforced Concrete Sleepers

by Arailym Imankulova, Murat Alimkulov, Baitak Apshikur, Medetbek Kambarov, Tolebi Myrzaliyev, Daniyar Akhmetov and Yelbek Utepov

J. Compos. Sci. 2026, 10(5), 240; https://doi.org/10.3390/jcs10050240 - 29 Apr 2026

Abstract

Improving the durability of reinforced concrete sleepers is essential for railway infrastructure exposed to dynamic loading, moisture, and repeated freeze–thaw action. This study proposes a material-level modification approach for heavy concrete for type 2 reinforced concrete sleepers based on the combined use of [...] Read more.

Improving the durability of reinforced concrete sleepers is essential for railway infrastructure exposed to dynamic loading, moisture, and repeated freeze–thaw action. This study proposes a material-level modification approach for heavy concrete for type 2 reinforced concrete sleepers based on the combined use of activated microsilica, a ferroalloy-production byproduct, electrolyzed mixing water, and a polycarboxylate superplasticizer. The novelty of the work lies in the preliminary electrochemical activation of microsilica in an alkaline medium and in the optimization of its joint use with KN-5 by means of second-order experimental design. The concrete was evaluated by compressive and bending strength tests, scanning electron microscopy (SEM), water-penetration testing, and freeze–thaw resistance testing. All modified mixtures outperformed the reference concrete. The highest 28-day compressive strength reached 67.0 MPa, while bending strength reached 7.26 MPa. SEM observations showed a denser and more homogeneous cement matrix with reduced capillary porosity and improved interfacial transition zones. Water resistance improved from W8 for the reference mixture to W10–W14 for the modified concretes. Most modified mixtures achieved a frost resistance grade of F500, and the composition containing 15% activated microsilica and 1.0% superplasticizer reached F550. The proposed approach is effective at the material level for producing heavy concrete with enhanced strength and durability characteristics for reinforced concrete sleeper applications. Full article

(This article belongs to the Special Issue From Waste to Advance Composite Materials, 2nd Edition)

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18 pages, 7511 KB

Open AccessArticle

Study of Microwave Characteristics and Compressive Strength of Mg_0.5Zn_0.5Fe₂O₄/Polystyrene/Activated Carbon Composites with Core-Shell Structure

by Dauren B. Kadyrzhanov, Rafael I. Shakirzyanov, Kanat M. Makhanov, Sofiya A. Maznykh and Dilnaz K. Zhamikhanova

J. Compos. Sci. 2026, 10(5), 239; https://doi.org/10.3390/jcs10050239 - 29 Apr 2026

Abstract

Due to the widespread use of microwave electromagnetic radiation, this study examines the microwave electromagnetic properties and compressive strength of composites made from inexpensive components such as Mg_0.5Zn_0.5Fe₂O₄, polystyrene, and activated carbon. Experimental samples were [...] Read more.

Due to the widespread use of microwave electromagnetic radiation, this study examines the microwave electromagnetic properties and compressive strength of composites made from inexpensive components such as Mg_0.5Zn_0.5Fe₂O₄, polystyrene, and activated carbon. Experimental samples were fabricated using thermopressing. The formation of the dielectric core/shell structure for Mg-Zn/polystyrene composites (1:1) and composites with activated carbon additives at weight concentrations of 3, 6.6, and 9.0% was determined using SEM image analysis. Microwave properties were investigated by analyzing the frequency dependences of complex permittivity and magnetic permeability in the frequency range of 100 MHz–5 GHz. As shown by the simulation and experimental measurements of scattering parameters obtained, the compost shows improved microwave absorption properties in the frequency range of 1–5 GHz. Reflection loss spectra showed peaks with values of −17.8 and −18 dB in the frequency range of 2.5–5 GHz for samples with 4.8 wt. % and 6.6 wt. % carbon loading, respectively. The absorption bandwidths of −10 dB in the range of 1.7–2.13 GHz were observed in the best samples. Studies have shown that samples containing 9.0 wt. % of carbon material with thicknesses of 6–10 mm can be considered as an electromagnetic shielding material in the microwave range 1–5 GHz. It was shown that, despite a decrease in porosity from 15.59 to 7.17%, with an increase in the concentration of carbon material in the composites, the compressive strength also decreases from 62.05 to 36.45 MPa. The developed composites are potentially suitable as microwave absorbers for civil applications. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2026)

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22 pages, 85676 KB

Open AccessArticle

Mechanical Strength Analysis of Silt-Filled, NaOH-KOH Activated Metakaolin-Based Geopolymers

by Francesca Ranellucci, Gianfranco Ulian, Daniele Moro, Cesare Sangiorgi and Giovanni Valdrè

J. Compos. Sci. 2026, 10(5), 238; https://doi.org/10.3390/jcs10050238 - 29 Apr 2026

Abstract

The present study reports the variation of the mechanical properties of engineered metakaolin-based geopolymers synthetized using NaOH-KOH alkali activators and sodium disilicate, investigated after 7 and 28 days of aging by means of unconfined compression tests for mechanical strength analysis. The geopolymers were [...] Read more.

The present study reports the variation of the mechanical properties of engineered metakaolin-based geopolymers synthetized using NaOH-KOH alkali activators and sodium disilicate, investigated after 7 and 28 days of aging by means of unconfined compression tests for mechanical strength analysis. The geopolymers were synthetized by mixing KOH and NaOH in different proportions in the alkaline activating solution, from 0% to 100% of KOH addition, fixing the Si/Al ratio and water content. The binders were synthetized with different curing temperatures. A novel composition using quarry-derived materials (silt from sedimentation lakes) was developed to realize an innovative composite. The materials were characterized by XRD, ESEM-EDS and unconfined compression tests. The mechanical results underlined that the addition of the filler tends to preserve the mechanical properties of the composite. Generally, curing at 40 °C followed by a 28-day aging period for the mixed Na-K geopolymers demonstrated the highest mechanical strength of all the synthesized products, with a maximum strength of 21 MPa. Mixed NaOH-KOH composites generally exhibited lower performances compared to sample consisting solely of 100% NaOH when cured at a temperature of 85 °C. Nonetheless, the synthetized composites reported in this study can have diverse applications across various technological fields requiring low-strength materials. Full article

(This article belongs to the Special Issue Recent Advancements in Mechanical Properties of Composites)

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25 pages, 6892 KB

Open AccessArticle

Synergistic and Antagonistic Interactions of Zinc Oxide/Magnesium Oxide Activation Systems and Ground Tire Rubber on the Properties of Styrene–Butadiene Rubber-Based Composites

by Samara Araújo Kawall, Nuelson Carlitos Gomes, Diego Silva de Melo, Dener da Silva Souza, Ricardo Henrique dos Santos, Naiara Lima Costa, Camila Liendra Rausis Hiranobe, Elmer Mateus Gennaro, Flávio Camargo Cabrera, Michael Jones da Silva, Leandro Ferreira Pinto, Erivaldo Antonio da Silva, Carlos Toshiyuki Hiranobe and Renivaldo José dos Santos

J. Compos. Sci. 2026, 10(5), 237; https://doi.org/10.3390/jcs10050237 - 29 Apr 2026

Abstract

This study evaluated the partial and total replacement of zinc oxide (ZnO) with magnesium oxide (MgO) in styrene–butadiene rubber (SBR) composites, as well as the incorporation of ground tire rubber (GTR), aiming to develop more sustainable elastomer formulations. Ten formulations were prepared with [...] Read more.

This study evaluated the partial and total replacement of zinc oxide (ZnO) with magnesium oxide (MgO) in styrene–butadiene rubber (SBR) composites, as well as the incorporation of ground tire rubber (GTR), aiming to develop more sustainable elastomer formulations. Ten formulations were prepared with varying ZnO/MgO ratios (100/0 to 0/100), with and without 20 phr of GTR. The composites were characterized by particle size distribution, morphology, rheometric behavior, density, crosslink density, mechanical properties, abrasion resistance, compression behavior, and thermo-oxidative aging. The results showed that hybrid ZnO/MgO activation systems exhibited a synergistic effect, enhancing vulcanization kinetics and mechanical performance compared to single-activator systems. Total replacement of ZnO by MgO was less effective, leading to reduced crosslink density and inferior properties. The addition of GTR increased compound viscosity and altered morphology but improved abrasion and compression resistance without significantly affecting tensile strength. Aging tests indicated good thermal stability, with maintenance or improvement of tensile properties due to post-curing effects. Overall, the combination of reduced ZnO content with MgO and GTR represents a viable approach for producing SBR composites with adequate performance and lower environmental impact. Full article

(This article belongs to the Section Polymer Composites)

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28 pages, 2383 KB

Open AccessArticle

A Scripting-Based Finite Element Framework for Parametric Analysis of Concrete-Filled Tubes Under Cyclic Bending

by Angelo Angrisani, Paolo Todisco, Alessandro Pisapia and Francesco Fabbrocino

J. Compos. Sci. 2026, 10(5), 236; https://doi.org/10.3390/jcs10050236 - 28 Apr 2026

Abstract

This paper investigates the low-cycle behaviour of Concrete-Filled steel Tubes (CFTs) subjected to cyclic pure bending, a loading condition representative of large bridge and building girders. A 3D finite element model is developed in Abaqus/Explicit, combining a ductile damage law for the steel [...] Read more.

This paper investigates the low-cycle behaviour of Concrete-Filled steel Tubes (CFTs) subjected to cyclic pure bending, a loading condition representative of large bridge and building girders. A 3D finite element model is developed in Abaqus/Explicit, combining a ductile damage law for the steel tube and Concrete-Damaged Plasticity for the infilled concrete, and is calibrated against large-scale cyclic bending tests on circular and square CFT beams. An automated Python scripting framework is then used to perform a systematic parametric study on members made of standard code-based materials, varying diameter-to-thickness ratio and span length over a wide range of practical configurations. Constant-amplitude chord rotations are imposed, and the nonlinear response is tracked in the plastic range while material damage evolves. The hysteretic behaviour is quantified in terms of cumulative plastic strains, dissipated energy and the degradation of reaction force and bending moment after 25 cycles. The results show that geometric parameters strongly affect the cyclic response: within the investigated loading layer, configurations with D_e = 100 mm generally exhibit strength degradation values between about 10% and 60%, whereas for D_e = 400 mm the degradation typically ranges between 50% and 100%, with most cases falling in the moderate-to-severe degradation domain. At the same time, larger diameters and thicker tubes generally lead to an increase in dissipated energy, while longer members tend to show lower energy dissipation but also reduced degradation. The study therefore provides a reproducible computational framework and comparative performance trends for the assessment of low-cycle cyclic response in CFT beams under a prescribed loading protocol. Full article

(This article belongs to the Special Issue Concrete Composites in Hybrid Structures)

19 pages, 3812 KB

Open AccessArticle

Experimental and RSM-Based Investigation of the Crashworthiness Characteristics of Aluminium/Carbon Hybrid Composites Under Axial Loading

by Tabrej Khan, Rahul Chamola, Harri Junaedi and Tamer A. Sebaey

J. Compos. Sci. 2026, 10(5), 235; https://doi.org/10.3390/jcs10050235 - 28 Apr 2026

Abstract

Metal–polymer hybrid composites blend the high strength and stiffness of metals with the low weight and corrosion resistance of polymers. This synergy is expected to provide better crashworthiness, energy absorption, and design flexibility compared to traditional single-material structures. The present research intended to [...] Read more.

Metal–polymer hybrid composites blend the high strength and stiffness of metals with the low weight and corrosion resistance of polymers. This synergy is expected to provide better crashworthiness, energy absorption, and design flexibility compared to traditional single-material structures. The present research intended to examine the crashworthiness features of an aluminium/CFRP structure under various operating conditions by optimizing process parameters through Design Expert software and experimental investigation. The design of the experiment was carried out using Design Expert software version 13 with response surface methodology (RSM) where working temperature, isothermal holding time, and crushing speed are taken as process variables. The test results demonstrate that the peak load, energy absorption (EA), and specific energy absorption (SEA) are significantly higher for the sample with working temperature, isothermal holding time, and crushing speed set at 25 °C, 13 h, and 5 mm/min, respectively. Moreover, EA and SEA are also relatively higher for this sample compared to the other samples. The test results showcased that temperature is a decisive factor for the mechanical properties of the tube, which is clearly reflected in experimental results. The higher peak force and EA indicate greater strength and a more energy-dissipative system. Moreover, a close correlation was observed between the experimentally measured and RSM-based optimization. Hence, RSM was found to be suitable for designing the experiments and for understanding the failure modes of the CFRP/aluminium structure. Full article

(This article belongs to the Section Fiber Composites)

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13 pages, 3038 KB

Open AccessArticle

Rhombic Bistable Composites with Integrated Pneumatic Actuation and Cylindrical Curved Shapes

by Zefeng Xu, Shi Liu, Qicai Ren, Yi Yang, Tao Tao, Xinran Guo, Yitong Zhou, Jiaqiao Liang and Peiyu Liu

J. Compos. Sci. 2026, 10(5), 234; https://doi.org/10.3390/jcs10050234 - 27 Apr 2026

Abstract

This study proposes a novel pneumatically driven mechanically prestressed rhombic bistable composite laminate with asymmetric cylindrical curvature, which exhibits two weakly-coupled cylindrical shapes where each shape is influenced by planform and geometry parameters. A reduced-order analytical model is developed to predict the laminate’s [...] Read more.

This study proposes a novel pneumatically driven mechanically prestressed rhombic bistable composite laminate with asymmetric cylindrical curvature, which exhibits two weakly-coupled cylindrical shapes where each shape is influenced by planform and geometry parameters. A reduced-order analytical model is developed to predict the laminate’s quasi-static equilibrium shapes and snap-through transitions of the laminate under pneumatic work loading, which is triggered by the internal pressure applied to the fluidic channels. A sensitivity study based on the model investigates the influence of key planform and geometric parameters (the internal angle α and aspect ratio E) on the laminate’s out-of-plane deflection and snap-through pressure. The results show that increasing α reduces the critical prestrain required to achieve bistability and amplifies the out-of-plane deflection, while excessive α may lead to monostable curvature. Variations in aspect ratio modify the coupling stiffness between orthogonal PEMC layers, thereby influencing the bistable domain and critical snap-through pressure. These findings provide methods for the design of bistable composite structures. Full article

(This article belongs to the Section Composites Modelling and Characterization)

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24 pages, 8335 KB

Open AccessArticle

Study on Low-Velocity Impact Resistance of SMA-CFRP U-Shaped Structure Considering Curing Residual Stress

by Liangdi Wang, Yingjie Xu, Jun Wang and Shengnan Zhang

J. Compos. Sci. 2026, 10(5), 233; https://doi.org/10.3390/jcs10050233 - 27 Apr 2026

Abstract

While carbon fiber-reinforced polymer (CFRP) composites are widely utilized in aerospace applications due to their exceptional specific strength and stiffness, they are inevitably subjected to impact loads during service, which can easily induce internal damage such as delamination. To mitigate these issues, this [...] Read more.

While carbon fiber-reinforced polymer (CFRP) composites are widely utilized in aerospace applications due to their exceptional specific strength and stiffness, they are inevitably subjected to impact loads during service, which can easily induce internal damage such as delamination. To mitigate these issues, this study investigates the low-velocity impact behavior of an SMA-reinforced CFRP U-shaped structure, emphasizing the critical role of curing-induced residual stresses. A numerical model incorporating the thermal-mechanical manufacturing history was developed and validated against experimental data. Results indicate that while embedded superelastic SMA wires effectively suppress crack propagation and enhance energy absorption, neglecting residual stresses leads to a significant overestimation of structural rigidity and peak loads. Due to the coefficient of thermal expansion mismatch between the SMA wires and the resin matrix, the SMA-CFRP system exhibits higher sensitivity to initial internal stresses than pure CFRP. By accounting for the residual stress field, the relative error in predicted peak force and absorbed energy for the SMA-CFRP model was reduced from 9.3% to 3.5% and 18.9% to 7.8%, respectively. These findings demonstrate that residual stress lowers the failure threshold and is essential for capturing the synergistic effects of SMA phase transformation and matrix damage, providing a more accurate reconstruction of the structural energy balance. Full article

(This article belongs to the Special Issue Structural Design, Health Monitoring and Performance Evaluation of Composite Materials)

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15 pages, 1474 KB

Open AccessArticle

The Effect of Solid-Phase and Melt Synthesis Methods on Dipole Ordering and Ion Conductivity of the Polar α-Phase of Na₃Fe₂(PO₄)₃ Polycrystals

by A. S. Nogai, A. A. Nogai, E. A. Nogai, N. F. Zikrillaev, D. E. Uskenbaev, A. B. Utegulov and K. U. Muhamedrahimov

J. Compos. Sci. 2026, 10(5), 232; https://doi.org/10.3390/jcs10050232 - 27 Apr 2026

Abstract

The article investigates the dielectric and conductive properties of the polar α-phase of Na₃Fe₂(PO₄)₃ polycrystals synthesized by solid-phase (sample type 1), melt (type 2), and melt-quenching (type 3) methods. To enable a rapid assessment of the [...] Read more.

The article investigates the dielectric and conductive properties of the polar α-phase of Na₃Fe₂(PO₄)₃ polycrystals synthesized by solid-phase (sample type 1), melt (type 2), and melt-quenching (type 3) methods. To enable a rapid assessment of the dielectric properties of the polar α-phase of Na₃Fe₂(PO₄)₃, the thermo-polarization mobility parameter μ_Tp(T, E(ω)) was introduced. By studying the dielectric properties, it was concluded that the polar α-phase of type 1 samples consists of large and small dipoles and ordered sodium cations, which possess low values of μ_Tp(T, E(ω)), indicating the presence of strong interaction forces between the crystal lattice and the cationic part of the polycrystal. Additional studies of the samples’ conductivity confirm this conclusion. Studies of the polar α-phase of Na₃Fe₂(PO₄)₃ in type 2 samples have established that their structure contains dipoles and sodium cations with higher values of μ_Tr(T, E(ω)), and also exhibits higher conductivity than Type 1 samples. These data indicate a weakening of the interaction forces between the cationic and anionic components in type 2 polycrystals due to a partial increase in crystal symmetry. The results of studies of the polar α-phase of type 3 samples show that their structure contains dipoles and sodium cations with higher values of μ_Tr(T, E(ω)), and also exhibits higher conductivity than type 2 samples. It is concluded that the structure of type 3 samples is characterized by weak interaction forces between the cationic and anionic parts as a result of an increase in the symmetry of the polar α-phase of Na₃Fe₂(PO₄)₃, caused by sharply graded temperature conditions during the synthesis of polycrystals. By studying the dielectric properties of cathode materials, it is possible to obtain information on the extent of interactions between the cationic and anionic components in polycrystals. It is, therefore, appropriate to use this approach when investigating a wide range of new dielectric and ion-conducting materials. Full article

(This article belongs to the Section Composites Applications)

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15 pages, 659 KB

Open AccessArticle

Parameter-Free Metaheuristic-Based Method for Reinforced Concrete Frame Cost Optimization

by Elmas Rakıcı Güldal, Sinan Melih Nigdeli, Gebrail Bekdaş and Zong Woo Geem

J. Compos. Sci. 2026, 10(5), 231; https://doi.org/10.3390/jcs10050231 - 26 Apr 2026

Abstract

This study proposes a parameter-free metaheuristic optimization framework using the Jaya and Rao algorithms for the cost-based design of reinforced concrete (RC) frames in accordance with ACI 318-25. Beam and column dimensions are treated as design variables within predefined bounds, and the objective [...] Read more.

This study proposes a parameter-free metaheuristic optimization framework using the Jaya and Rao algorithms for the cost-based design of reinforced concrete (RC) frames in accordance with ACI 318-25. Beam and column dimensions are treated as design variables within predefined bounds, and the objective was to minimize the total construction cost including concrete and reinforcing steel. Structural analysis was performed using the matrix displacement method. The performance of the Jaya, Rao-1, Rao-2, and Rao-3 algorithms was evaluated through multiple independent runs. All methods achieved optimal or near-optimal solutions; however, Rao-2 demonstrated competitive performance with low mean values and favorable statistical performance. The results confirm the effectiveness of parameter-free metaheuristic methods for RC structural cost optimization. Unlike previous studies, this study explicitly focuses on parameter-free metaheuristic algorithms and evaluates their robustness through statistical analysis on reinforced concrete frame systems. The main contribution lies in demonstrating the comparative performance and practical applicability of parameter-free algorithms without the need for algorithm-specific parameter tuning. Full article

(This article belongs to the Special Issue Automated and Digital Construction of Low-Carbon and High-Performance Steel-Concrete Composite Systems)

19 pages, 7224 KB

Open AccessArticle

Experimental Investigation of Low-Velocity Impact Response and Damage Behavior in Mono, Bi- and Tri-Hybrid Fiber-Reinforced Composites

by Md. Mominur Rahman, Al Emran Ismail, Muhammad Faiz Ramli, Azrin Hani Abdul Rashid, Tabrej Khan, Omar Shabbir Ahmed and Tamer A. Sebaey

J. Compos. Sci. 2026, 10(5), 230; https://doi.org/10.3390/jcs10050230 - 26 Apr 2026

Abstract

The need to create lightweight materials with better mechanical properties has led to the use of Fiber Reinforced Composites (FRCs)s in the aerospace and automotive industries. The mechanical behavior of FRCs is heterogeneous, especially in conditions of low-velocity impact (LVI). The impact events [...] Read more.

The need to create lightweight materials with better mechanical properties has led to the use of Fiber Reinforced Composites (FRCs)s in the aerospace and automotive industries. The mechanical behavior of FRCs is heterogeneous, especially in conditions of low-velocity impact (LVI). The impact events cause structural damage, where most of the available literature deals with mono- or bi-composites in controlled situations. This work will present the results of studying the behavior of mono, bi- and tri-hybrids with carbon, glass and Kevlar fiber-reinforced epoxy. The sequences of the laminate stacks, number of plies and laminate thickness in the drop weight testing were across velocities of 1.91 to 3.91 m/s at drop heights of 19 to 79 cm. The dominant pillars of LVI, such as peak load, energy absorption and the modes of damage, were analyzed. The glass-dominated laminates peaked at 5.67 kN, while the Kevlar-dominated laminates reached peak flow in ductile collapse with greater quantities of absorbed energy. The leaders in strength and energy were the hybrids of Kevlar–glass (KG) cross-ply at 8.08 kN and 47.28 J and quasi-isotropic Kevlar–carbon–glass (KCG) at 9.12 kN and 47.25 J, showcasing a balance of strength and toughness. The rest, holding a greater quantity of Kevlar, ranging in thickness and cross-plies, were shaped with a load center. The experimental conclusion is that hybridization improved impact resistance and ductility, which is best supported by the glass/carbon rigidity-layered laminates. Such understanding directs the design work of future composite materials for better impact control. Full article

(This article belongs to the Special Issue Composite Production and Performance Evaluation for Upcoming Transportation Technologies)

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22 pages, 1371 KB

Open AccessArticle

Analytic Hierarchy Process-Based Multi-Criteria Optimization of Functionally Graded Thermoplastic Architectures for Enhanced Viscoelastic Energy Dissipation

by Raja Subramani

J. Compos. Sci. 2026, 10(5), 229; https://doi.org/10.3390/jcs10050229 - 25 Apr 2026

Abstract

Functionally graded multi-material thermoplastic architectures provide a promising route for tailoring viscoelastic energy dissipation through controlled phase contrast and interfacial interactions. However, rational selection of optimal material compositions remains challenging due to competing requirements among stiffness, damping efficiency, thermal stability, and processability. The [...] Read more.

Functionally graded multi-material thermoplastic architectures provide a promising route for tailoring viscoelastic energy dissipation through controlled phase contrast and interfacial interactions. However, rational selection of optimal material compositions remains challenging due to competing requirements among stiffness, damping efficiency, thermal stability, and processability. The absence of a quantitative decision framework often limits systematic design of architected polymer systems. This study proposes an Analytic Hierarchy Process (AHP)-based multi-criteria decision model to identify the optimal rigid–elastic thermoplastic composition for enhanced damping performance. Nine performance criteria were considered, including storage modulus, loss factor, damping bandwidth, interfacial adhesion strength, elongation at break, impact resistance, glass transition temperature, thermal stability, and printability. Fourteen alternative material configurations combining different rigid phases, elastomeric interlayers, filler contents, and layer thickness ratios were evaluated. Pairwise comparison matrices were constructed based on experimentally measured thermomechanical data and literature-reported values, and consistency ratios were maintained below 0.1 to ensure decision reliability. Numerical results indicate that a graded PLA/soft-TPU/PLA architecture with optimized layer thickness ratio achieved the highest global priority weight (0.431), outperforming the baseline PLA/TPU system by approximately ~25–30% in overall performance index. Sensitivity analysis confirmed ranking robustness across variations in damping and stiffness weighting factors. The proposed framework establishes a systematic methodology for polymer material selection and multi-material architectural optimization, enabling data-driven design of thermoplastic systems with tunable viscoelastic performance. Full article

(This article belongs to the Section Composites Manufacturing and Processing)

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19 pages, 4058 KB

Open AccessArticle

Assessing the Environmental Sustainability of Agro-Waste Fiber-Reinforced PLA Composites Through Life Cycle Assessment

by Vikas Yadav, Akshay Dvivedi and Subrata Chandra Das

J. Compos. Sci. 2026, 10(5), 228; https://doi.org/10.3390/jcs10050228 - 24 Apr 2026

Abstract

Agricultural residues and agro-waste are increasingly recognized as valuable reinforcements for sustainable composite materials. Natural fibers derived from these biomasses offer biodegradability, low density, renewability, and potential environmental benefits. However, their performance and sustainability depend strongly on extraction, surface treatment, and processing conditions. [...] Read more.

Agricultural residues and agro-waste are increasingly recognized as valuable reinforcements for sustainable composite materials. Natural fibers derived from these biomasses offer biodegradability, low density, renewability, and potential environmental benefits. However, their performance and sustainability depend strongly on extraction, surface treatment, and processing conditions. Therefore, evaluating the environmental emissions associated with natural fiber biocomposites is essential before claiming sustainability advantages. In this research, flax, jute, kenaf, and bagasse fibers were extracted and treated using an eco-friendly sodium bicarbonate solution, then incorporated into polylactic acid (PLA) matrix to fabricate biocomposites via injection molding. A life cycle assessment (LCA) was conducted using the ReCiPe midpoint (H) method, with a functional unit defined as “per kg” of manufactured biocomposite. The results revealed that jute fiber composites generated the highest emissions across several impact categories, including climate change (1.290 × 10¹ kg CO₂-Eq), terrestrial ecotoxicity (6.327 × 10¹ kg 1,4-DCB-Eq), human toxicity: carcinogenic effects (1.923 kg 1,4-DCB-Eq), and fossil resource use (3.202 kg oil-Eq). Jute also showed a 3.6% increase in terrestrial ecotoxicity and a 19.5% increase in land compared to flax, although it exhibited a 6.5% lower impact related to bagasse. A ±20% electricity-consumption sensitivity analysis further highlighted the dependence of environmental impacts on processing energy demand. Full article

(This article belongs to the Special Issue Natural Fiber Composites (NFCs)—Current Research Trends and Applications)

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17 pages, 6384 KB

Open AccessArticle

Influence of Fabrication Methods of Polyetherimide-Based Composites Reinforced with Carbon Fabrics on Their Structures and Mechanical Properties

by Ziyi Peng, Vladislav O. Alexenko, Alexey A. Bogdanov, Dmitry G. Buslovich, Shaowei Lu and Sergey V. Panin

J. Compos. Sci. 2026, 10(5), 227; https://doi.org/10.3390/jcs10050227 - 24 Apr 2026

Abstract

In this study, the structure and mechanical properties of composites fabricated by polyetherimide film and powder lamination of carbon fabrics, as well as their impregnation with a polyetherimide/N-methylpyrrolidone solution at different contents, were compared. At compression sintering pressure of 10 MPa, the most [...] Read more.

In this study, the structure and mechanical properties of composites fabricated by polyetherimide film and powder lamination of carbon fabrics, as well as their impregnation with a polyetherimide/N-methylpyrrolidone solution at different contents, were compared. At compression sintering pressure of 10 MPa, the most uniform structure with the minimum number of discontinuities was formed by film lamination at the maximum carbon fabric content of 70 wt.%. For powder lamination, some discontinuities were found in the composites, which may be caused by the low melt flow index of the polyetherimide powder. The composites fabricated by impregnation with the dissolved PEI possessed low mechanical properties, so the compression sintering pressure was reduced to 6 MPa. After that, an improved composite was characterized by both uniform structure and high mechanical properties (even above those at film lamination), confirming the effectiveness of this fabrication method. Full article

(This article belongs to the Special Issue Continuous Fiber-Reinforced Composite Materials: Processes, Structures and Properties)

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86 pages, 2405 KB

Open AccessReview

Decarbonising the Cement and Concrete Industry—A Step Forward to a Sustainable Future

by Salmabanu Luhar, Ashraf Ashour and Ismail Luhar

J. Compos. Sci. 2026, 10(5), 226; https://doi.org/10.3390/jcs10050226 - 23 Apr 2026

Abstract

Despite being fundamental to modern infrastructure, the cement and concrete industry is a major contributor to global carbon emissions, necessitating urgent decarbonisation strategies to mitigate climate change and achieve net-zero targets by 2050. This review explores technological pathways and innovations essential for lowering [...] Read more.

Despite being fundamental to modern infrastructure, the cement and concrete industry is a major contributor to global carbon emissions, necessitating urgent decarbonisation strategies to mitigate climate change and achieve net-zero targets by 2050. This review explores technological pathways and innovations essential for lowering carbon emissions, including low-carbon materials, energy-efficient processes, carbon capture, utilization and storage (CCUS), and advanced production technologies. It also highlights the importance of supportive policy frameworks, financial incentives, and international collaboration in accelerating the transition to a low-carbon industry. While challenges such as high initial costs, resistance to change, and knowledge gaps persist, these can be addressed through innovation, education, and robust financial mechanisms. Furthermore, circular economy principles, sustainable procurement practices, and continued research and development are emphasized as critical enablers of the industry’s transformation. The paper concludes with recommendations for future actions, highlighting the role of cross-sector cooperation, research funding, and knowledge sharing in achieving a sustainable and decarbonised cement and concrete sector that can “go green” for eco-constructions. Full article

(This article belongs to the Special Issue Sustainable Composite Construction Materials, 3rd Edition)

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19 pages, 14339 KB

Open AccessArticle

Damage Evolution of CNT Interleaves Under Mode I and Mode II Fractures of Laminates: Experimental and Numerical Investigation

by Junyang Chen, Zhouyi Li, Ying Wang, Yuwen Wang and Jinhu Shi

J. Compos. Sci. 2026, 10(5), 225; https://doi.org/10.3390/jcs10050225 - 23 Apr 2026

Abstract

This work reveals the interlaminar fracture behavior and failure modes of carbon nanotube (CNT) film toughening composite laminates under Mode I and Mode II fractures. Experiment results display that the Mode I fracture toughness increases to its maximum value when a 2-layer CNT [...] Read more.

This work reveals the interlaminar fracture behavior and failure modes of carbon nanotube (CNT) film toughening composite laminates under Mode I and Mode II fractures. Experiment results display that the Mode I fracture toughness increases to its maximum value when a 2-layer CNT film is added, then it decreases with the increase in CNT layers. However, the trend changes with the number of CNT layers under Mode II fracture, that is, the fracture toughness gradually increases with the increase in CNT layers. This result indicates that compared to a Mode II fracture, the toughening effect of multi-layer CNT under a Mode I fracture has not been effectively produced. A novel micro-mechanical model, based on a Voronoi diagram, is established to identify the failure mode within the CNT toughening region. It is shown that the crack propagation paths of the two kinds of fracture modes are different: cracks propagate along the CNT/resin interface for Mode I fracture, while propagating simultaneously at both the interface and resin for Mode II fracture. The change in failure mode of the CNT toughening region is the reason for the various effects under the two-fracture loading. This work innovatively utilizes finite element simulation and cross-sectional micro characterization methods to reveal the differences in interlayer failure modes of CNT film interlayer toughening materials under different fracture modes, aiming to provide guidance for the application of CNT films in the field of interlayer toughening. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Modeling and Simulation of Composite Materials, 2nd Edition)

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30 pages, 34327 KB

Open AccessArticle

Development of 3D-Printed Electrically Conductive Photopolymer Resins Modified with PEDOT:PSS and Nano-Graphite

by Marco Conti, Tommaso Rossi, Simone Serrecchia, Antonella Macagnano and Emiliano Zampetti

J. Compos. Sci. 2026, 10(5), 224; https://doi.org/10.3390/jcs10050224 - 23 Apr 2026

Abstract

Electrically conductive photopolymers enable the fabrication of functional 3D-printed components with customized electrical properties, expanding additive manufacturing applications beyond traditional structural uses. This study reports the formulation and characterization of electrically conductive, water-washable photopolymer resins for masked stereolithography (MSLA) through the incorporation of [...] Read more.

Electrically conductive photopolymers enable the fabrication of functional 3D-printed components with customized electrical properties, expanding additive manufacturing applications beyond traditional structural uses. This study reports the formulation and characterization of electrically conductive, water-washable photopolymer resins for masked stereolithography (MSLA) through the incorporation of nano-graphite, PEDOT:PSS, and dimethyl sulfoxide (DMSO) as a secondary dopant. Single filler and hybrid resin systems were prepared and processed via MSLA printing, then subjected to sequential thermal treatments, 25 °C curing for 48 h followed by annealing at 80 °C and 120 °C, to investigate conductivity enhancement and microstructural evolution. Electrical characterization via current–voltage (I–V) measurements, referenced to the transversal conductivity (

σ_{T R A}

), showed that the hybrid formulation containing PEDOT:PSS, graphite, and DMSO achieved the highest conductivity (9.40 × 10⁻² S·cm⁻¹), outperforming PEDOT:PSS/graphite systems (2.6 × 10⁻³ S·cm⁻¹) and graphite-only samples (9.76 × 10⁻⁴ S·cm⁻¹). Conductivity increased consistently after each thermal step, indicating enhanced charge transport. Scanning electron microscopy further revealed improved filler dispersion and interconnectivity within the polymer matrix. The synergistic combination of PEDOT:PSS, graphite nanofillers, and DMSO enables MSLA printed components with tunable and reproducible electrical performance. This work demonstrates a scalable strategy for producing functional, water-washable photopolymer resins suitable for applications in sensors, soft electronics, and lightweight conductive structures. Full article

(This article belongs to the Special Issue 3D Printing and Additive Manufacturing of Composites, 2nd Edition)

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27 pages, 18982 KB

Open AccessArticle

Composite Materials Based on Bioresorbable Polymers and Phosphate Phases for Bone Tissue Regeneration

by Oana Maria Caramidaru, Celina Maria Damian, Gianina Popescu-Pelin, Mihaela Bacalum, Roberta Moisa, Cornelia-Ioana Ilie, Sorin-Ion Jinga and Cristina Busuioc

J. Compos. Sci. 2026, 10(5), 223; https://doi.org/10.3390/jcs10050223 - 23 Apr 2026

Abstract

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth [...] Read more.

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg²⁺) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg₂P₂O₇) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article

(This article belongs to the Special Issue Biomedical Composite Applications)

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